monaco-yaml-5.1.0.tgz: 1 vulnerabilities (highest severity is: 4.3)

[mend-bolt-for-github]

Vulnerable Library - monaco-yaml-5.1.0.tgz

Path to dependency file: /playground/package.json

Path to vulnerable library: /playground/node_modules/yaml/package.json

Found in HEAD commit: 1fc76088d115ca2a2f6ae32d49d53ed791dd82df

Vulnerabilities

Vulnerability	Severity	CVSS	Dependency	Type	Fixed in (monaco-yaml version)	Remediation Possible**
CVE-2026-33532	Medium	4.3	yaml-2.3.4.tgz	Transitive	N/A*	❌

*For some transitive vulnerabilities, there is no version of direct dependency with a fix. Check the "Details" section below to see if there is a version of transitive dependency where vulnerability is fixed.

**In some cases, Remediation PR cannot be created automatically for a vulnerability despite the availability of remediation

Details

CVE-2026-33532

Vulnerable Library - yaml-2.3.4.tgz

Library home page: https://registry.npmjs.org/yaml/-/yaml-2.3.4.tgz

Path to dependency file: /playground/package.json

Path to vulnerable library: /playground/node_modules/yaml/package.json

Dependency Hierarchy:

• monaco-yaml-5.1.0.tgz (Root Library)
  • ❌ yaml-2.3.4.tgz (Vulnerable Library)

Found in HEAD commit: 1fc76088d115ca2a2f6ae32d49d53ed791dd82df

Found in base branch: develop

Vulnerability Details

Parsing a YAML document with "yaml" may throw a RangeError due to a stack overflow. The node resolution/composition phase uses recursive function calls without a depth bound. An attacker who can supply YAML for parsing can trigger a "RangeError: Maximum call stack size exceeded" with a small payload (~2–10 KB). The "RangeError" is not a "YAMLParseError", so applications that only catch YAML-specific errors will encounter an unexpected exception type. Depending on the host application's exception handling, this can fail requests or terminate the Node.js process. Flow sequences allow deep nesting with minimal bytes (2 bytes per level: one "[" and one "]"). On the default Node.js stack, approximately 1,000–5,000 levels of nesting (2–10 KB input) exhaust the call stack. The exact threshold is environment-dependent (Node.js version, stack size, call stack depth at invocation). Note: the library's "Parser" (CST phase) uses a stack-based iterative approach and is not affected. Only the compose/resolve phase uses actual call-stack recursion. All three public parsing APIs are affected: "YAML.parse()", "YAML.parseDocument()", and "YAML.parseAllDocuments()". PoC const YAML = require('yaml'); // ~10 KB payload: 5000 levels of nested flow sequences const payload = '['.repeat(5000) + '1' + ']'.repeat(5000); try { YAML.parse(payload); } catch (e) { console.log(e.constructor.name); // RangeError (NOT YAMLParseError) console.log(e.message); // Maximum call stack size exceeded } Test environment: Node.js v24.12.0, macOS darwin arm64 | Version | Nesting Depth | Input Size | Result | |---|---|---|---| | 1.0.0 | 5,000 | 10,001 B | RangeError | | 1.10.2 | 5,000 | 10,001 B | RangeError | | 2.0.0 | 5,000 | 10,001 B | RangeError | | 2.8.2 | 5,000 | 10,001 B | RangeError | | 2.8.3 | 5,000 | 10,001 B | YAMLParseError | Depth threshold on yaml 2.8.2: | Nesting Depth | Input Size | Result | |---|---|---| | 500 | 1,001 B | Parses successfully | | 1,000 | 2,001 B | RangeError (threshold varies by stack size) | | 5,000 | 10,001 B | RangeError |

Publish Date: 2026-03-25

URL: CVE-2026-33532

CVSS 3 Score Details (4.3)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: Low
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: Low

For more information on CVSS3 Scores, click here.

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[mend-bolt-for-github]

✔️ This issue was automatically closed by Mend because the vulnerable library in the specific branch(es) was either marked as ignored or it is no longer part of the Mend inventory.

[mend-bolt-for-github]

ℹ️ This issue was automatically re-opened by Mend because the vulnerable library in the specific branch(es) has been detected in the Mend inventory.