openssl_encrypt versions before 1.4.9 derive the remote-pepper wrap key using unsalted HKDF-SHA256 or bare SHA-256 of the password, allowing identical keys across all users and files. Attackers with access to wrapped pepper blobs can precompute a single dictionary table and perform fleet-wide offline password guessing at hardware speed to recover user passwords.
HIGH
Vulnerability intelligence
CVE-2026-81689
CVSS 4.08.7
SeverityHigh
Known exploitedNo
NVD references:
Primary source: NIST National Vulnerability Database