{
  "cve_id": "CVE-2026-5479",
  "reproduced": true,
  "verdict": "confirmed",
  "reproduction_script": "repro/reproduction_steps.sh",
  "vulnerable_version": "wolfSSL v5.9.0-stable",
  "fixed_version": "wolfSSL v5.9.1-stable",
  "issue_type": "AEAD integrity-check bypass (CWE-354)",
  "summary": "wolfSSL's EVP compatibility API for ChaCha20-Poly1305 decryption (wolfSSL_EVP_CipherFinal) fails to verify the Poly1305 authentication tag before returning decrypted plaintext. This allows forged or modified ciphertext to be accepted as authentic.",
  "details": {
    "trigger": "EVP ChaCha20-Poly1305 decrypt path via wolfSSL_EVP_CipherFinal with a forged tag, random bad tag, or modified ciphertext",
    "vulnerable_behavior": "EVP_DecryptFinal_ex returns success (1) on all three tampered inputs: zeroed tag, random bad tag, and flipped ciphertext byte with correct tag. The decrypted plaintext is returned without any integrity verification.",
    "fixed_behavior": "EVP_DecryptFinal_ex returns failure (0) on all three tampered inputs, correctly rejecting forged tags and modified ciphertext.",
    "api_under_test": "wolfSSL_EVP_CipherFinal (ChaCha20-Poly1305 decrypt path in wolfcrypt/src/evp.c)",
    "tamper_strategies": [
      "zeroed_authentication_tag",
      "random_authentication_tag",
      "flipped_ciphertext_byte_with_correct_tag"
    ],
    "vulnerable_results": {
      "test1_zeroed_tag": {
        "EVP_DecryptFinal_ex_return": 1,
        "behavior": "accepted_forged_tag"
      },
      "test2_random_tag": {
        "EVP_DecryptFinal_ex_return": 1,
        "behavior": "accepted_forged_tag"
      },
      "test3_modified_ciphertext": {
        "EVP_DecryptFinal_ex_return": 1,
        "behavior": "accepted_modified_ciphertext"
      }
    },
    "fixed_results": {
      "test1_zeroed_tag": {
        "EVP_DecryptFinal_ex_return": 0,
        "behavior": "rejected_forged_tag"
      },
      "test2_random_tag": {
        "EVP_DecryptFinal_ex_return": 0,
        "behavior": "rejected_forged_tag"
      },
      "test3_modified_ciphertext": {
        "EVP_DecryptFinal_ex_return": 0,
        "behavior": "rejected_modified_ciphertext"
      }
    },
    "logs": [
      "logs/vulnerable_output.txt",
      "logs/fixed_output.txt",
      "logs/runtime_manifest.json"
    ]
  }
}