CVE-2026-74900
CRITICAL
NVD
CVSS Score
9.8
Severity
CRITICAL
Published
Aug 17, 2026
Vendor
unknown
Description
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.