From 3925e16e3283901efce44359f617cc26ab909c56 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Fri, 30 Jan 2026 23:28:34 -0300
Subject: [PATCH 01/15] chore: add mnemonic validation method

---
 packages/keyring-eth-hd/package.json          |  5 +-
 .../keyring-eth-hd/src/hd-keyring.test.ts     | 81 ++++++++++++++++++-
 packages/keyring-eth-hd/src/hd-keyring.ts     | 34 ++++++++
 yarn.lock                                     | 67 ++++++++++++++-
 4 files changed, 183 insertions(+), 4 deletions(-)

diff --git a/packages/keyring-eth-hd/package.json b/packages/keyring-eth-hd/package.json
index 0658f4ecb..1ed147474 100644
--- a/packages/keyring-eth-hd/package.json
+++ b/packages/keyring-eth-hd/package.json
@@ -45,6 +45,7 @@
   "dependencies": {
     "@ethereumjs/tx": "^5.4.0",
     "@ethereumjs/util": "^9.1.0",
+    "@ethersproject/hdnode": "^5.8.0",
     "@metamask/eth-sig-util": "^8.2.0",
     "@metamask/key-tree": "^10.0.2",
     "@metamask/keyring-api": "workspace:^",
@@ -77,7 +78,9 @@
     "allowScripts": {
       "@lavamoat/preinstall-always-fail": false,
       "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false,
-      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false
+      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false,
+      "old-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false,
+      "old-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false
     }
   }
 }
diff --git a/packages/keyring-eth-hd/src/hd-keyring.test.ts b/packages/keyring-eth-hd/src/hd-keyring.test.ts
index 6d410fa09..f65c188e0 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.test.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.test.ts
@@ -250,7 +250,7 @@ describe('hd-keyring', () => {
       expect(cryptographicFunctions.pbkdf2Sha512).toHaveBeenCalledTimes(1);
     });
 
-    it('throws on invalid mnemonic', async () => {
+    it('throws on invalid mnemonic with wrong number of words', async () => {
       const keyring = new HdKeyring();
 
       await expect(
@@ -259,10 +259,87 @@ describe('hd-keyring', () => {
           numberOfAccounts: 2,
         }),
       ).rejects.toThrow(
-        'Invalid mnemonic phrase: The mnemonic phrase must consist of 12, 15, 18, 21, or 24 words.',
+        'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
       );
     });
 
+    it('throws on mnemonic with invalid words', async () => {
+      const keyring = new HdKeyring();
+
+      // 12 words but invalid (not in BIP39 wordlist)
+      await expect(
+        keyring.deserialize({
+          mnemonic:
+            'invalid words that are not in the bip39 wordlist at all here',
+          numberOfAccounts: 1,
+        }),
+      ).rejects.toThrow(
+        'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
+      );
+    });
+
+    it('throws on mnemonic with invalid checksum', async () => {
+      const keyring = new HdKeyring();
+
+      // Valid BIP39 words but invalid checksum (last word changed from 'mango' to 'abandon')
+      await expect(
+        keyring.deserialize({
+          mnemonic:
+            'finish oppose decorate face calm tragic certain desk hour urge dinosaur abandon',
+          numberOfAccounts: 1,
+        }),
+      ).rejects.toThrow(
+        'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
+      );
+    });
+
+    it('throws on invalid mnemonic passed as Buffer', async () => {
+      const keyring = new HdKeyring();
+
+      // Invalid mnemonic as raw Buffer
+      await expect(
+        keyring.deserialize({
+          // @ts-expect-error testing Buffer mnemonic directly
+          mnemonic: Buffer.from('invalid mnemonic phrase here', 'utf8'),
+          numberOfAccounts: 1,
+        }),
+      ).rejects.toThrow(
+        'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
+      );
+    });
+
+    it('deserializes valid mnemonic passed as Buffer', async () => {
+      const keyring = new HdKeyring();
+
+      await keyring.deserialize({
+        // @ts-expect-error testing Buffer mnemonic directly
+        mnemonic: Buffer.from(sampleMnemonic, 'utf8'),
+        numberOfAccounts: 1,
+      });
+
+      const accounts = await keyring.getAccounts();
+      expect(accounts[0]).toStrictEqual(firstAcct);
+    });
+
+    it('validates mnemonic passed as Uint8Array with valid mnemonic', async () => {
+      const keyring = new HdKeyring();
+
+      // Serialize a valid keyring to get the Uint8Array format
+      const tempKeyring = new HdKeyring();
+      await tempKeyring.deserialize({ mnemonic: sampleMnemonic });
+      const { mnemonic } = tempKeyring;
+      assert(mnemonic, 'Mnemonic should be defined');
+
+      await keyring.deserialize({
+        // @ts-expect-error testing Uint8Array mnemonic directly
+        mnemonic,
+        numberOfAccounts: 1,
+      });
+
+      const accounts = await keyring.getAccounts();
+      expect(accounts[0]).toStrictEqual(firstAcct);
+    });
+
     it('throws when numberOfAccounts is passed with no mnemonic', async () => {
       const keyring = new HdKeyring();
 
diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index a4b09b827..ce30195b6 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -1,5 +1,6 @@
 import type { TypedTransaction } from '@ethereumjs/tx';
 import { privateToPublic, publicToAddress, ecsign } from '@ethereumjs/util';
+import { isValidMnemonic } from '@ethersproject/hdnode';
 import {
   concatSig,
   decrypt,
@@ -610,6 +611,7 @@ export class HdKeyring implements Keyring {
       );
     }
 
+    this.#validateMnemonic(mnemonic);
     this.mnemonic = this.#mnemonicToUint8Array(mnemonic);
 
     this.seed = await mnemonicToSeed(
@@ -644,4 +646,36 @@ export class HdKeyring implements Keyring {
     assert(normalized, 'Expected address to be set');
     return add0x(normalized);
   }
+
+  /**
+   * Validate the mnemonic seed phrase.
+   *
+   * @param mnemonic - The mnemonic seed phrase to validate.
+   * @throws If the mnemonic is invalid.
+   */
+  #validateMnemonic(
+    mnemonic: string | number[] | SerializedBuffer | Buffer | Uint8Array,
+  ): void {
+    let mnemonicString: string;
+
+    if (typeof mnemonic === 'string') {
+      mnemonicString = mnemonic;
+    } else if (Array.isArray(mnemonic)) {
+      mnemonicString = Buffer.from(mnemonic).toString();
+    } else if (isSerializedBuffer(mnemonic)) {
+      mnemonicString = Buffer.from(mnemonic.data).toString();
+    } else if (Buffer.isBuffer(mnemonic)) {
+      mnemonicString = mnemonic.toString();
+    } else if (mnemonic instanceof Uint8Array) {
+      mnemonicString = this.#uint8ArrayToString(mnemonic);
+    } else {
+      throw new Error('Eth-Hd-Keyring: Invalid mnemonic format');
+    }
+
+    if (!isValidMnemonic(mnemonicString)) {
+      throw new Error(
+        'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
+      );
+    }
+  }
 }
diff --git a/yarn.lock b/yarn.lock
index 81a8e5f45..dddf87b3c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -673,6 +673,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ethersproject/basex@npm:^5.8.0":
+  version: 5.8.0
+  resolution: "@ethersproject/basex@npm:5.8.0"
+  dependencies:
+    "@ethersproject/bytes": "npm:^5.8.0"
+    "@ethersproject/properties": "npm:^5.8.0"
+  checksum: 10/1a8d48a9397461ea42ec43b69a15a0d13ba0b9192695713750d9d391503c55b258cca435fa78a4014d23a813053f1a471593b89c7c0d89351639a78d50a12ef2
+  languageName: node
+  linkType: hard
+
 "@ethersproject/bignumber@npm:^5.7.0, @ethersproject/bignumber@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/bignumber@npm:5.8.0"
@@ -702,7 +712,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ethersproject/hash@npm:^5.7.0":
+"@ethersproject/hash@npm:^5.7.0, @ethersproject/hash@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/hash@npm:5.8.0"
   dependencies:
@@ -719,6 +729,26 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ethersproject/hdnode@npm:^5.8.0":
+  version: 5.8.0
+  resolution: "@ethersproject/hdnode@npm:5.8.0"
+  dependencies:
+    "@ethersproject/abstract-signer": "npm:^5.8.0"
+    "@ethersproject/basex": "npm:^5.8.0"
+    "@ethersproject/bignumber": "npm:^5.8.0"
+    "@ethersproject/bytes": "npm:^5.8.0"
+    "@ethersproject/logger": "npm:^5.8.0"
+    "@ethersproject/pbkdf2": "npm:^5.8.0"
+    "@ethersproject/properties": "npm:^5.8.0"
+    "@ethersproject/sha2": "npm:^5.8.0"
+    "@ethersproject/signing-key": "npm:^5.8.0"
+    "@ethersproject/strings": "npm:^5.8.0"
+    "@ethersproject/transactions": "npm:^5.8.0"
+    "@ethersproject/wordlists": "npm:^5.8.0"
+  checksum: 10/55b35cf30f0dd40e2d5ecd4b2f005ebea82a85a440717a61d4a483074f652d2c7063e9c704272b894bfdd500f7883aa36692931c6808591f702c1da7107ebb61
+  languageName: node
+  linkType: hard
+
 "@ethersproject/keccak256@npm:^5.7.0, @ethersproject/keccak256@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/keccak256@npm:5.8.0"
@@ -745,6 +775,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ethersproject/pbkdf2@npm:^5.8.0":
+  version: 5.8.0
+  resolution: "@ethersproject/pbkdf2@npm:5.8.0"
+  dependencies:
+    "@ethersproject/bytes": "npm:^5.8.0"
+    "@ethersproject/sha2": "npm:^5.8.0"
+  checksum: 10/203bb992eec3042256702f4c8259a37202af7b341cc6e370614cdc52541042fc3b795fb040592bd6be8b67376a798c45312ca1e6d5d179c3e8eb7431882f1fd1
+  languageName: node
+  linkType: hard
+
 "@ethersproject/properties@npm:^5.7.0, @ethersproject/properties@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/properties@npm:5.8.0"
@@ -764,6 +804,17 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ethersproject/sha2@npm:^5.8.0":
+  version: 5.8.0
+  resolution: "@ethersproject/sha2@npm:5.8.0"
+  dependencies:
+    "@ethersproject/bytes": "npm:^5.8.0"
+    "@ethersproject/logger": "npm:^5.8.0"
+    hash.js: "npm:1.1.7"
+  checksum: 10/ef8916e3033502476fba9358ba1993722ac3bb99e756d5681e4effa3dfa0f0bf0c29d3fa338662830660b45dd359cccb06ba40bc7b62cfd44f4a177b25829404
+  languageName: node
+  linkType: hard
+
 "@ethersproject/signing-key@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/signing-key@npm:5.8.0"
@@ -819,6 +870,19 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ethersproject/wordlists@npm:^5.8.0":
+  version: 5.8.0
+  resolution: "@ethersproject/wordlists@npm:5.8.0"
+  dependencies:
+    "@ethersproject/bytes": "npm:^5.8.0"
+    "@ethersproject/hash": "npm:^5.8.0"
+    "@ethersproject/logger": "npm:^5.8.0"
+    "@ethersproject/properties": "npm:^5.8.0"
+    "@ethersproject/strings": "npm:^5.8.0"
+  checksum: 10/b8e6aa7d2195bb568847f360f6525ddc3d145404fbd4553e2e05daf4a95f58167591feb69e16e3398a28114ea85e1895fc8f5bd1c0cbf8b578123d7c1d21c32d
+  languageName: node
+  linkType: hard
+
 "@fivebinaries/coin-selection@npm:3.0.0":
   version: 3.0.0
   resolution: "@fivebinaries/coin-selection@npm:3.0.0"
@@ -1684,6 +1748,7 @@ __metadata:
   dependencies:
     "@ethereumjs/tx": "npm:^5.4.0"
     "@ethereumjs/util": "npm:^9.1.0"
+    "@ethersproject/hdnode": "npm:^5.8.0"
     "@lavamoat/allow-scripts": "npm:^3.2.1"
     "@lavamoat/preinstall-always-fail": "npm:^2.1.0"
     "@metamask/account-api": "workspace:^"

From 3b0d05d528baaf4e8aea27d225e963ea286a6f4a Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Fri, 30 Jan 2026 23:34:05 -0300
Subject: [PATCH 02/15] chore: update CHANGELOG

---
 packages/keyring-eth-hd/CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/keyring-eth-hd/CHANGELOG.md b/packages/keyring-eth-hd/CHANGELOG.md
index 92f6ebf13..6aaa3ed0c 100644
--- a/packages/keyring-eth-hd/CHANGELOG.md
+++ b/packages/keyring-eth-hd/CHANGELOG.md
@@ -12,6 +12,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add `HdKeyringV2` class implementing `KeyringV2` interface ([#398](https://github.com/MetaMask/accounts/pull/398)), ([#404](https://github.com/MetaMask/accounts/pull/404)), ([#410](https://github.com/MetaMask/accounts/pull/410)), ([#413](https://github.com/MetaMask/accounts/pull/413))
   - Wraps legacy `HdKeyring` to expose accounts via the unified `KeyringV2` API and the `KeyringAccount` type.
   - Extends `EthKeyringWrapper` for common Ethereum logic.
+- Add mnemonic validation using `@ethersproject/hdnode`
+  - Validates mnemonics against BIP39 specification (word count, wordlist, checksum) before use.
+  - Throws for invalid mnemonics.
 
 ## [13.0.0]
 

From 7adb29bbfef783b6899a7d90845db6eb4d04b2f2 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 12:35:33 -0300
Subject: [PATCH 03/15] refactor: use validateMnemonic from
 @metamask/scure-bip39

---
 packages/keyring-eth-hd/CHANGELOG.md      | 4 ++--
 packages/keyring-eth-hd/package.json      | 1 -
 packages/keyring-eth-hd/src/hd-keyring.ts | 9 ++++-----
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/packages/keyring-eth-hd/CHANGELOG.md b/packages/keyring-eth-hd/CHANGELOG.md
index 6aaa3ed0c..5abcab410 100644
--- a/packages/keyring-eth-hd/CHANGELOG.md
+++ b/packages/keyring-eth-hd/CHANGELOG.md
@@ -12,9 +12,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add `HdKeyringV2` class implementing `KeyringV2` interface ([#398](https://github.com/MetaMask/accounts/pull/398)), ([#404](https://github.com/MetaMask/accounts/pull/404)), ([#410](https://github.com/MetaMask/accounts/pull/410)), ([#413](https://github.com/MetaMask/accounts/pull/413))
   - Wraps legacy `HdKeyring` to expose accounts via the unified `KeyringV2` API and the `KeyringAccount` type.
   - Extends `EthKeyringWrapper` for common Ethereum logic.
-- Add mnemonic validation using `@ethersproject/hdnode`
+- Add mnemonic validation using `validateMnemonic` from `@metamask/scure-bip39`
   - Validates mnemonics against BIP39 specification (word count, wordlist, checksum) before use.
-  - Throws for invalid mnemonics.
+  - Throws `'Eth-Hd-Keyring: Invalid secret recovery phrase provided'` for invalid mnemonics.
 
 ## [13.0.0]
 
diff --git a/packages/keyring-eth-hd/package.json b/packages/keyring-eth-hd/package.json
index 1ed147474..4c29dcb9a 100644
--- a/packages/keyring-eth-hd/package.json
+++ b/packages/keyring-eth-hd/package.json
@@ -45,7 +45,6 @@
   "dependencies": {
     "@ethereumjs/tx": "^5.4.0",
     "@ethereumjs/util": "^9.1.0",
-    "@ethersproject/hdnode": "^5.8.0",
     "@metamask/eth-sig-util": "^8.2.0",
     "@metamask/key-tree": "^10.0.2",
     "@metamask/keyring-api": "workspace:^",
diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index ce30195b6..b55f6577f 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -1,6 +1,5 @@
 import type { TypedTransaction } from '@ethereumjs/tx';
 import { privateToPublic, publicToAddress, ecsign } from '@ethereumjs/util';
-import { isValidMnemonic } from '@ethersproject/hdnode';
 import {
   concatSig,
   decrypt,
@@ -21,7 +20,7 @@ import {
   mnemonicToSeed,
 } from '@metamask/key-tree';
 import type { Keyring } from '@metamask/keyring-utils';
-import { generateMnemonic } from '@metamask/scure-bip39';
+import { generateMnemonic, validateMnemonic } from '@metamask/scure-bip39';
 import { wordlist } from '@metamask/scure-bip39/dist/wordlists/english';
 import {
   add0x,
@@ -611,7 +610,7 @@ export class HdKeyring implements Keyring {
       );
     }
 
-    this.#validateMnemonic(mnemonic);
+    this.#isValidMnemonic(mnemonic);
     this.mnemonic = this.#mnemonicToUint8Array(mnemonic);
 
     this.seed = await mnemonicToSeed(
@@ -653,7 +652,7 @@ export class HdKeyring implements Keyring {
    * @param mnemonic - The mnemonic seed phrase to validate.
    * @throws If the mnemonic is invalid.
    */
-  #validateMnemonic(
+  #isValidMnemonic(
     mnemonic: string | number[] | SerializedBuffer | Buffer | Uint8Array,
   ): void {
     let mnemonicString: string;
@@ -672,7 +671,7 @@ export class HdKeyring implements Keyring {
       throw new Error('Eth-Hd-Keyring: Invalid mnemonic format');
     }
 
-    if (!isValidMnemonic(mnemonicString)) {
+    if (!validateMnemonic(mnemonicString, wordlist)) {
       throw new Error(
         'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
       );

From 1ce9033d23321746e68bb9edcc03f933f7451b09 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 14:24:46 -0300
Subject: [PATCH 04/15] fix: handle mnemonic as object

---
 .../keyring-eth-hd/src/hd-keyring.test.ts     | 23 +++++++
 packages/keyring-eth-hd/src/hd-keyring.ts     | 17 +++--
 yarn.lock                                     | 67 +------------------
 3 files changed, 35 insertions(+), 72 deletions(-)

diff --git a/packages/keyring-eth-hd/src/hd-keyring.test.ts b/packages/keyring-eth-hd/src/hd-keyring.test.ts
index f65c188e0..8edd327e2 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.test.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.test.ts
@@ -340,6 +340,29 @@ describe('hd-keyring', () => {
       expect(accounts[0]).toStrictEqual(firstAcct);
     });
 
+    it('validates mnemonic passed as plain object (simulating encryption/decryption cycle)', async () => {
+      const keyring = new HdKeyring();
+
+      const tempKeyring = new HdKeyring();
+      await tempKeyring.deserialize({ mnemonic: sampleMnemonic });
+      const { mnemonic } = tempKeyring;
+      assert(mnemonic, 'Mnemonic should be defined');
+
+      const mnemonicAsPlainObject: Record<string, number> = {};
+      mnemonic.forEach((value, index) => {
+        mnemonicAsPlainObject[index] = value;
+      });
+
+      await keyring.deserialize({
+        // @ts-expect-error testing plain object mnemonic directly
+        mnemonic: mnemonicAsPlainObject,
+        numberOfAccounts: 1,
+      });
+
+      const accounts = await keyring.getAccounts();
+      expect(accounts[0]).toStrictEqual(firstAcct);
+    });
+
     it('throws when numberOfAccounts is passed with no mnemonic', async () => {
       const keyring = new HdKeyring();
 
diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index b55f6577f..1daec7bf8 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -38,6 +38,8 @@ import { keccak256 } from 'ethereum-cryptography/keccak';
 const hdPathString = `m/44'/60'/0'/0`;
 const type = 'HD Key Tree';
 
+type Mnemonic = string | number[] | SerializedBuffer | Buffer | Uint8Array;
+
 export type HDKeyringOptions = {
   cryptographicFunctions?: CryptographicFunctions;
 };
@@ -601,9 +603,7 @@ export class HdKeyring implements Keyring {
    * as a string, an array of UTF-8 bytes, or a Buffer. Mnemonic input
    * passed as type buffer or array of UTF-8 bytes must be NFKD normalized.
    */
-  async #initFromMnemonic(
-    mnemonic: string | number[] | SerializedBuffer | Buffer | Uint8Array,
-  ): Promise<void> {
+  async #initFromMnemonic(mnemonic: Mnemonic): Promise<void> {
     if (this.root) {
       throw new Error(
         'Eth-Hd-Keyring: Secret recovery phrase already provided',
@@ -652,9 +652,7 @@ export class HdKeyring implements Keyring {
    * @param mnemonic - The mnemonic seed phrase to validate.
    * @throws If the mnemonic is invalid.
    */
-  #isValidMnemonic(
-    mnemonic: string | number[] | SerializedBuffer | Buffer | Uint8Array,
-  ): void {
+  #isValidMnemonic(mnemonic: Mnemonic): void {
     let mnemonicString: string;
 
     if (typeof mnemonic === 'string') {
@@ -667,6 +665,13 @@ export class HdKeyring implements Keyring {
       mnemonicString = mnemonic.toString();
     } else if (mnemonic instanceof Uint8Array) {
       mnemonicString = this.#uint8ArrayToString(mnemonic);
+    } else if (typeof mnemonic === 'object') {
+      // When encrypted/decrypted, Uint8Arrays can become plain objects like {0: ..., 1: ..., ...}
+      // Convert back to Uint8Array first, then to mnemonic string
+      const mnemonicAsUint8Array = Uint8Array.from(
+        Object.values(mnemonic as Record<string, number>),
+      );
+      mnemonicString = this.#uint8ArrayToString(mnemonicAsUint8Array);
     } else {
       throw new Error('Eth-Hd-Keyring: Invalid mnemonic format');
     }
diff --git a/yarn.lock b/yarn.lock
index dddf87b3c..81a8e5f45 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -673,16 +673,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ethersproject/basex@npm:^5.8.0":
-  version: 5.8.0
-  resolution: "@ethersproject/basex@npm:5.8.0"
-  dependencies:
-    "@ethersproject/bytes": "npm:^5.8.0"
-    "@ethersproject/properties": "npm:^5.8.0"
-  checksum: 10/1a8d48a9397461ea42ec43b69a15a0d13ba0b9192695713750d9d391503c55b258cca435fa78a4014d23a813053f1a471593b89c7c0d89351639a78d50a12ef2
-  languageName: node
-  linkType: hard
-
 "@ethersproject/bignumber@npm:^5.7.0, @ethersproject/bignumber@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/bignumber@npm:5.8.0"
@@ -712,7 +702,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ethersproject/hash@npm:^5.7.0, @ethersproject/hash@npm:^5.8.0":
+"@ethersproject/hash@npm:^5.7.0":
   version: 5.8.0
   resolution: "@ethersproject/hash@npm:5.8.0"
   dependencies:
@@ -729,26 +719,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ethersproject/hdnode@npm:^5.8.0":
-  version: 5.8.0
-  resolution: "@ethersproject/hdnode@npm:5.8.0"
-  dependencies:
-    "@ethersproject/abstract-signer": "npm:^5.8.0"
-    "@ethersproject/basex": "npm:^5.8.0"
-    "@ethersproject/bignumber": "npm:^5.8.0"
-    "@ethersproject/bytes": "npm:^5.8.0"
-    "@ethersproject/logger": "npm:^5.8.0"
-    "@ethersproject/pbkdf2": "npm:^5.8.0"
-    "@ethersproject/properties": "npm:^5.8.0"
-    "@ethersproject/sha2": "npm:^5.8.0"
-    "@ethersproject/signing-key": "npm:^5.8.0"
-    "@ethersproject/strings": "npm:^5.8.0"
-    "@ethersproject/transactions": "npm:^5.8.0"
-    "@ethersproject/wordlists": "npm:^5.8.0"
-  checksum: 10/55b35cf30f0dd40e2d5ecd4b2f005ebea82a85a440717a61d4a483074f652d2c7063e9c704272b894bfdd500f7883aa36692931c6808591f702c1da7107ebb61
-  languageName: node
-  linkType: hard
-
 "@ethersproject/keccak256@npm:^5.7.0, @ethersproject/keccak256@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/keccak256@npm:5.8.0"
@@ -775,16 +745,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ethersproject/pbkdf2@npm:^5.8.0":
-  version: 5.8.0
-  resolution: "@ethersproject/pbkdf2@npm:5.8.0"
-  dependencies:
-    "@ethersproject/bytes": "npm:^5.8.0"
-    "@ethersproject/sha2": "npm:^5.8.0"
-  checksum: 10/203bb992eec3042256702f4c8259a37202af7b341cc6e370614cdc52541042fc3b795fb040592bd6be8b67376a798c45312ca1e6d5d179c3e8eb7431882f1fd1
-  languageName: node
-  linkType: hard
-
 "@ethersproject/properties@npm:^5.7.0, @ethersproject/properties@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/properties@npm:5.8.0"
@@ -804,17 +764,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ethersproject/sha2@npm:^5.8.0":
-  version: 5.8.0
-  resolution: "@ethersproject/sha2@npm:5.8.0"
-  dependencies:
-    "@ethersproject/bytes": "npm:^5.8.0"
-    "@ethersproject/logger": "npm:^5.8.0"
-    hash.js: "npm:1.1.7"
-  checksum: 10/ef8916e3033502476fba9358ba1993722ac3bb99e756d5681e4effa3dfa0f0bf0c29d3fa338662830660b45dd359cccb06ba40bc7b62cfd44f4a177b25829404
-  languageName: node
-  linkType: hard
-
 "@ethersproject/signing-key@npm:^5.8.0":
   version: 5.8.0
   resolution: "@ethersproject/signing-key@npm:5.8.0"
@@ -870,19 +819,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@ethersproject/wordlists@npm:^5.8.0":
-  version: 5.8.0
-  resolution: "@ethersproject/wordlists@npm:5.8.0"
-  dependencies:
-    "@ethersproject/bytes": "npm:^5.8.0"
-    "@ethersproject/hash": "npm:^5.8.0"
-    "@ethersproject/logger": "npm:^5.8.0"
-    "@ethersproject/properties": "npm:^5.8.0"
-    "@ethersproject/strings": "npm:^5.8.0"
-  checksum: 10/b8e6aa7d2195bb568847f360f6525ddc3d145404fbd4553e2e05daf4a95f58167591feb69e16e3398a28114ea85e1895fc8f5bd1c0cbf8b578123d7c1d21c32d
-  languageName: node
-  linkType: hard
-
 "@fivebinaries/coin-selection@npm:3.0.0":
   version: 3.0.0
   resolution: "@fivebinaries/coin-selection@npm:3.0.0"
@@ -1748,7 +1684,6 @@ __metadata:
   dependencies:
     "@ethereumjs/tx": "npm:^5.4.0"
     "@ethereumjs/util": "npm:^9.1.0"
-    "@ethersproject/hdnode": "npm:^5.8.0"
     "@lavamoat/allow-scripts": "npm:^3.2.1"
     "@lavamoat/preinstall-always-fail": "npm:^2.1.0"
     "@metamask/account-api": "workspace:^"

From a130994d10c5f19503a4ca08cec0ada0b5b72ca2 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 14:26:45 -0300
Subject: [PATCH 05/15] chore: package.json

---
 packages/keyring-eth-hd/package.json | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/packages/keyring-eth-hd/package.json b/packages/keyring-eth-hd/package.json
index 4c29dcb9a..4558909e5 100644
--- a/packages/keyring-eth-hd/package.json
+++ b/packages/keyring-eth-hd/package.json
@@ -76,10 +76,7 @@
   "lavamoat": {
     "allowScripts": {
       "@lavamoat/preinstall-always-fail": false,
-      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false,
-      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false,
-      "old-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false,
-      "old-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false
+      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false
     }
   }
 }

From 81affefb63390a4922f96535b17aa20b05de8e5b Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 16:07:43 -0300
Subject: [PATCH 06/15] chore: package.json

---
 packages/keyring-eth-hd/package.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/keyring-eth-hd/package.json b/packages/keyring-eth-hd/package.json
index 4558909e5..50de58142 100644
--- a/packages/keyring-eth-hd/package.json
+++ b/packages/keyring-eth-hd/package.json
@@ -76,7 +76,7 @@
   "lavamoat": {
     "allowScripts": {
       "@lavamoat/preinstall-always-fail": false,
-      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false
-    }
+      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false,
+      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false    }
   }
 }

From b32937bced4ee6d3e6c74b72ba048547a1b6b04c Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 16:08:22 -0300
Subject: [PATCH 07/15] chore: package.json

---
 packages/keyring-eth-hd/package.json | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/keyring-eth-hd/package.json b/packages/keyring-eth-hd/package.json
index 50de58142..0658f4ecb 100644
--- a/packages/keyring-eth-hd/package.json
+++ b/packages/keyring-eth-hd/package.json
@@ -77,6 +77,7 @@
     "allowScripts": {
       "@lavamoat/preinstall-always-fail": false,
       "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>keccak": false,
-      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false    }
+      "@metamask/eth-hd-keyring>ethereumjs-util>ethereum-cryptography>secp256k1": false
+    }
   }
 }

From 5abe574b11f9f576850c1770cdf1d42539e987ca Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 16:13:01 -0300
Subject: [PATCH 08/15] refactor: isValidMnemonic

---
 packages/keyring-eth-hd/src/hd-keyring.ts | 27 ++++-------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index 1daec7bf8..4b7228057 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -484,7 +484,7 @@ export class HdKeyring implements Keyring {
    * @returns The Uint8Array mnemonic.
    */
   #mnemonicToUint8Array(
-    mnemonic: Buffer | SerializedBuffer | string | Uint8Array | number[],
+    mnemonic: Mnemonic,
   ): Uint8Array {
     let mnemonicData: unknown = mnemonic;
     // When using `Buffer.toJSON()`, the Buffer is serialized into an object
@@ -653,28 +653,9 @@ export class HdKeyring implements Keyring {
    * @throws If the mnemonic is invalid.
    */
   #isValidMnemonic(mnemonic: Mnemonic): void {
-    let mnemonicString: string;
-
-    if (typeof mnemonic === 'string') {
-      mnemonicString = mnemonic;
-    } else if (Array.isArray(mnemonic)) {
-      mnemonicString = Buffer.from(mnemonic).toString();
-    } else if (isSerializedBuffer(mnemonic)) {
-      mnemonicString = Buffer.from(mnemonic.data).toString();
-    } else if (Buffer.isBuffer(mnemonic)) {
-      mnemonicString = mnemonic.toString();
-    } else if (mnemonic instanceof Uint8Array) {
-      mnemonicString = this.#uint8ArrayToString(mnemonic);
-    } else if (typeof mnemonic === 'object') {
-      // When encrypted/decrypted, Uint8Arrays can become plain objects like {0: ..., 1: ..., ...}
-      // Convert back to Uint8Array first, then to mnemonic string
-      const mnemonicAsUint8Array = Uint8Array.from(
-        Object.values(mnemonic as Record<string, number>),
-      );
-      mnemonicString = this.#uint8ArrayToString(mnemonicAsUint8Array);
-    } else {
-      throw new Error('Eth-Hd-Keyring: Invalid mnemonic format');
-    }
+    // Reuse #mnemonicToUint8Array for format conversion to avoid duplication
+    const mnemonicAsUint8Array = this.#mnemonicToUint8Array(mnemonic);
+    const mnemonicString = this.#uint8ArrayToString(mnemonicAsUint8Array);
 
     if (!validateMnemonic(mnemonicString, wordlist)) {
       throw new Error(

From 7e31ce24e793309bc47c4d56285427a07b1f5cef Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 16:20:36 -0300
Subject: [PATCH 09/15] refactor: isValidMnemonic

---
 packages/keyring-eth-hd/src/hd-keyring.ts | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index 4b7228057..f1fba8cea 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -483,9 +483,7 @@ export class HdKeyring implements Keyring {
    * @param mnemonic - The mnemonic seed phrase.
    * @returns The Uint8Array mnemonic.
    */
-  #mnemonicToUint8Array(
-    mnemonic: Mnemonic,
-  ): Uint8Array {
+  #mnemonicToUint8Array(mnemonic: Mnemonic): Uint8Array {
     let mnemonicData: unknown = mnemonic;
     // When using `Buffer.toJSON()`, the Buffer is serialized into an object
     // with the structure `{ type: 'Buffer', data: [...] }`
@@ -610,8 +608,8 @@ export class HdKeyring implements Keyring {
       );
     }
 
-    this.#isValidMnemonic(mnemonic);
     this.mnemonic = this.#mnemonicToUint8Array(mnemonic);
+    this.#isValidMnemonic(this.mnemonic);
 
     this.seed = await mnemonicToSeed(
       this.mnemonic,
@@ -652,11 +650,8 @@ export class HdKeyring implements Keyring {
    * @param mnemonic - The mnemonic seed phrase to validate.
    * @throws If the mnemonic is invalid.
    */
-  #isValidMnemonic(mnemonic: Mnemonic): void {
-    // Reuse #mnemonicToUint8Array for format conversion to avoid duplication
-    const mnemonicAsUint8Array = this.#mnemonicToUint8Array(mnemonic);
-    const mnemonicString = this.#uint8ArrayToString(mnemonicAsUint8Array);
-
+  #isValidMnemonic(mnemonic: Uint8Array): void {
+    const mnemonicString = this.#uint8ArrayToString(mnemonic);
     if (!validateMnemonic(mnemonicString, wordlist)) {
       throw new Error(
         'Eth-Hd-Keyring: Invalid secret recovery phrase provided',

From 9b685f0b87537214897112928363707e3c492b56 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sat, 31 Jan 2026 16:26:18 -0300
Subject: [PATCH 10/15] chore: update CHANGELOG

---
 packages/keyring-eth-hd/CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/keyring-eth-hd/CHANGELOG.md b/packages/keyring-eth-hd/CHANGELOG.md
index 5abcab410..91e7183d6 100644
--- a/packages/keyring-eth-hd/CHANGELOG.md
+++ b/packages/keyring-eth-hd/CHANGELOG.md
@@ -14,7 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Extends `EthKeyringWrapper` for common Ethereum logic.
 - Add mnemonic validation using `validateMnemonic` from `@metamask/scure-bip39`
   - Validates mnemonics against BIP39 specification (word count, wordlist, checksum) before use.
-  - Throws `'Eth-Hd-Keyring: Invalid secret recovery phrase provided'` for invalid mnemonics.
+  - Throws for invalid mnemonics.
 
 ## [13.0.0]
 

From 49a7c6cf3887088f3e57e26f0a868bcd7b467305 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sun, 1 Feb 2026 21:15:36 -0300
Subject: [PATCH 11/15] fix: state error

---
 packages/keyring-eth-hd/src/hd-keyring.ts | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index f1fba8cea..df8167296 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -608,8 +608,11 @@ export class HdKeyring implements Keyring {
       );
     }
 
-    this.mnemonic = this.#mnemonicToUint8Array(mnemonic);
-    this.#isValidMnemonic(this.mnemonic);
+    // Convert and validate before assigning to instance property
+    // to avoid inconsistent state if validation fails
+    const mnemonicAsUint8Array = this.#mnemonicToUint8Array(mnemonic);
+    this.#isValidMnemonic(mnemonicAsUint8Array);
+    this.mnemonic = mnemonicAsUint8Array;
 
     this.seed = await mnemonicToSeed(
       this.mnemonic,

From 409afcb4fdf105eb58bc2f373b6c3384349f97e1 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Sun, 1 Feb 2026 22:03:53 -0300
Subject: [PATCH 12/15] chore: change method name

---
 packages/keyring-eth-hd/src/hd-keyring.ts | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index df8167296..3a0e8f985 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -611,7 +611,7 @@ export class HdKeyring implements Keyring {
     // Convert and validate before assigning to instance property
     // to avoid inconsistent state if validation fails
     const mnemonicAsUint8Array = this.#mnemonicToUint8Array(mnemonic);
-    this.#isValidMnemonic(mnemonicAsUint8Array);
+    this.#assertValidMnemonic(mnemonicAsUint8Array);
     this.mnemonic = mnemonicAsUint8Array;
 
     this.seed = await mnemonicToSeed(
@@ -648,12 +648,13 @@ export class HdKeyring implements Keyring {
   }
 
   /**
-   * Validate the mnemonic seed phrase.
+   * Assert that the mnemonic seed phrase is valid.
+   * Throws an error if the mnemonic is not a valid BIP39 phrase.
    *
-   * @param mnemonic - The mnemonic seed phrase to validate.
-   * @throws If the mnemonic is invalid.
+   * @param mnemonic - The mnemonic seed phrase to validate (as Uint8Array).
+   * @throws If the mnemonic is not a valid BIP39 secret recovery phrase.
    */
-  #isValidMnemonic(mnemonic: Uint8Array): void {
+  #assertValidMnemonic(mnemonic: Uint8Array): void {
     const mnemonicString = this.#uint8ArrayToString(mnemonic);
     if (!validateMnemonic(mnemonicString, wordlist)) {
       throw new Error(

From fa5cf4e097713eb4e12b26d83602f91dc0772314 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Mon, 2 Feb 2026 07:44:17 -0300
Subject: [PATCH 13/15] chore: update CHANGELOG

---
 packages/keyring-eth-hd/CHANGELOG.md | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/keyring-eth-hd/CHANGELOG.md b/packages/keyring-eth-hd/CHANGELOG.md
index 91e7183d6..cc0af24ba 100644
--- a/packages/keyring-eth-hd/CHANGELOG.md
+++ b/packages/keyring-eth-hd/CHANGELOG.md
@@ -12,7 +12,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add `HdKeyringV2` class implementing `KeyringV2` interface ([#398](https://github.com/MetaMask/accounts/pull/398)), ([#404](https://github.com/MetaMask/accounts/pull/404)), ([#410](https://github.com/MetaMask/accounts/pull/410)), ([#413](https://github.com/MetaMask/accounts/pull/413))
   - Wraps legacy `HdKeyring` to expose accounts via the unified `KeyringV2` API and the `KeyringAccount` type.
   - Extends `EthKeyringWrapper` for common Ethereum logic.
-- Add mnemonic validation using `validateMnemonic` from `@metamask/scure-bip39`
+
+### Fixed
+
+- Enforce mnemonics validation ([#450](https://github.com/MetaMask/accounts/pull/450))
   - Validates mnemonics against BIP39 specification (word count, wordlist, checksum) before use.
   - Throws for invalid mnemonics.
 

From 178169c10757537a3d84559a8f16784cfb036503 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Mon, 2 Feb 2026 07:45:52 -0300
Subject: [PATCH 14/15] chore: update DeserializableHDKeyringState type

---
 packages/keyring-eth-hd/src/hd-keyring.test.ts | 3 ---
 packages/keyring-eth-hd/src/hd-keyring.ts      | 2 +-
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/packages/keyring-eth-hd/src/hd-keyring.test.ts b/packages/keyring-eth-hd/src/hd-keyring.test.ts
index 8edd327e2..b6f6915a7 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.test.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.test.ts
@@ -299,7 +299,6 @@ describe('hd-keyring', () => {
       // Invalid mnemonic as raw Buffer
       await expect(
         keyring.deserialize({
-          // @ts-expect-error testing Buffer mnemonic directly
           mnemonic: Buffer.from('invalid mnemonic phrase here', 'utf8'),
           numberOfAccounts: 1,
         }),
@@ -312,7 +311,6 @@ describe('hd-keyring', () => {
       const keyring = new HdKeyring();
 
       await keyring.deserialize({
-        // @ts-expect-error testing Buffer mnemonic directly
         mnemonic: Buffer.from(sampleMnemonic, 'utf8'),
         numberOfAccounts: 1,
       });
@@ -331,7 +329,6 @@ describe('hd-keyring', () => {
       assert(mnemonic, 'Mnemonic should be defined');
 
       await keyring.deserialize({
-        // @ts-expect-error testing Uint8Array mnemonic directly
         mnemonic,
         numberOfAccounts: 1,
       });
diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index 3a0e8f985..06a5848a7 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -69,7 +69,7 @@ export type DeserializableHDKeyringState = Omit<
   SerializedHDKeyringState,
   'mnemonic'
 > & {
-  mnemonic: number[] | SerializedBuffer | string;
+  mnemonic: Mnemonic;
 };
 
 /**

From 5075bae74bd5f8c10b2301b6f0622c48c05f04a4 Mon Sep 17 00:00:00 2001
From: gantunesr <17601467+gantunesr@users.noreply.github.com>
Date: Mon, 2 Feb 2026 08:43:15 -0300
Subject: [PATCH 15/15] Revert "chore: update DeserializableHDKeyringState
 type"

This reverts commit 178169c10757537a3d84559a8f16784cfb036503.
---
 packages/keyring-eth-hd/src/hd-keyring.test.ts | 3 +++
 packages/keyring-eth-hd/src/hd-keyring.ts      | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/keyring-eth-hd/src/hd-keyring.test.ts b/packages/keyring-eth-hd/src/hd-keyring.test.ts
index b6f6915a7..8edd327e2 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.test.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.test.ts
@@ -299,6 +299,7 @@ describe('hd-keyring', () => {
       // Invalid mnemonic as raw Buffer
       await expect(
         keyring.deserialize({
+          // @ts-expect-error testing Buffer mnemonic directly
           mnemonic: Buffer.from('invalid mnemonic phrase here', 'utf8'),
           numberOfAccounts: 1,
         }),
@@ -311,6 +312,7 @@ describe('hd-keyring', () => {
       const keyring = new HdKeyring();
 
       await keyring.deserialize({
+        // @ts-expect-error testing Buffer mnemonic directly
         mnemonic: Buffer.from(sampleMnemonic, 'utf8'),
         numberOfAccounts: 1,
       });
@@ -329,6 +331,7 @@ describe('hd-keyring', () => {
       assert(mnemonic, 'Mnemonic should be defined');
 
       await keyring.deserialize({
+        // @ts-expect-error testing Uint8Array mnemonic directly
         mnemonic,
         numberOfAccounts: 1,
       });
diff --git a/packages/keyring-eth-hd/src/hd-keyring.ts b/packages/keyring-eth-hd/src/hd-keyring.ts
index 06a5848a7..3a0e8f985 100644
--- a/packages/keyring-eth-hd/src/hd-keyring.ts
+++ b/packages/keyring-eth-hd/src/hd-keyring.ts
@@ -69,7 +69,7 @@ export type DeserializableHDKeyringState = Omit<
   SerializedHDKeyringState,
   'mnemonic'
 > & {
-  mnemonic: Mnemonic;
+  mnemonic: number[] | SerializedBuffer | string;
 };
 
 /**