CVE-2026-74900 — openssl_encrypt before 1.4.0 Weak Shared Secret via PQC Simulation Mode
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 determinist…
Published: 2026-08-17 · CVSS: 9.3 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7