CVE-2026-74900
CriticalCVSS 9.8Summary
openssl_encrypt before version 1.4.0 contains a critical vulnerability in pqc.py where KEM decapsulation failures silently fall back to simulation mode, generating a deterministic shared secret from only 16 bytes of the private key and publicly available encapsulated key data. Attackers who obtain 16 bytes of the private key can compute the shared secret and decrypt all ciphertext, as the fallback triggers on any KEM failure without raising an error.
Risk Assessment
The risk is critical because even a partial private key leak (16 bytes) allows full decryption of all data, potentially leading to complete confidentiality compromise.
Recommendation
Immediately upgrade openssl_encrypt to version 1.4.0 or later to eliminate this vulnerability.
Original NVD description (English source)
openssl_encrypt versions before 1.4.0 contain a critical vulnerability in pqc.py where KEM decapsulation failures silently fall back to simulation mode, generating a deterministic shared secret from only 16 bytes of the private key and publicly available encapsulated key data. Attackers who obtain 16 bytes of the private key can compute the shared secret and decrypt all ciphertext, as the fallback triggers on any KEM failure without raising an error.