diff --git a/src/platform/silabs/SiWx/CHIPCryptoPALTinyCrypt.cpp b/src/platform/silabs/SiWx/CHIPCryptoPALTinyCrypt.cpp
index 2d46bdc81fea32..f173cd791ae903 100644
--- a/src/platform/silabs/SiWx/CHIPCryptoPALTinyCrypt.cpp
+++ b/src/platform/silabs/SiWx/CHIPCryptoPALTinyCrypt.cpp
@@ -878,8 +878,13 @@ CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::FELoad(const uint8_t * in, size_t in_l
 {
     CHIP_ERROR error = CHIP_NO_ERROR;
 
+    // Warning: SPAKE2+ Generate uses `kSpake2p_WS_Length = kP256_FE_Length + 8`
+    // (40-byte) > NUM_ECC_BYTES (32-byte)
     uECC_word_t tmp[2 * NUM_ECC_WORDS] = { 0 };
-    uECC_vli_bytesToNative(tmp, in, NUM_ECC_BYTES);
+
+    VerifyOrReturnError(in_len <= sizeof(tmp), CHIP_ERROR_INVALID_ARGUMENT);
+
+    uECC_vli_bytesToNative(tmp, in, static_cast<int>(in_len));
 
     uECC_vli_mmod((uECC_word_t *) fe, tmp, curve_n);
 
@@ -1003,14 +1008,17 @@ CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointCofactorMul(void * R)
 CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1sin, size_t w1sin_len)
 {
     CHIP_ERROR error = CHIP_NO_ERROR;
-    int result       = 0;
+    int result       = UECC_SUCCESS;
+
+    // Warning: SPAKE2+ Generate uses `kSpake2p_WS_Length = kP256_FE_Length + 8`
+    // (40-byte) > NUM_ECC_BYTES (32-byte)
+    uECC_word_t tmp[2 * NUM_ECC_WORDS]   = { 0 };
+    uECC_word_t w1_bn[NUM_ECC_WORDS]     = { 0 };
+    uECC_word_t L_tmp[2 * NUM_ECC_WORDS] = { 0 };
 
-    result = UECC_SUCCESS;
-    uECC_word_t tmp[2 * NUM_ECC_WORDS];
-    uECC_word_t w1_bn[NUM_ECC_WORDS];
-    uECC_word_t L_tmp[2 * NUM_ECC_WORDS];
+    VerifyOrExit(w1sin_len <= sizeof(tmp), error = CHIP_ERROR_INVALID_ARGUMENT);
 
-    uECC_vli_bytesToNative(tmp, w1sin, NUM_ECC_BYTES);
+    uECC_vli_bytesToNative(tmp, w1sin, static_cast<int>(w1sin_len));
 
     uECC_vli_mmod(w1_bn, tmp, curve_n);