CVE-2026-81688
HighCVSS 7.5Summary
openssl_encrypt before version 1.4.9 stores an unkeyed SHA-256 hash of the plaintext in the cleartext file header. Attackers without the password can read this hash to confirm guessed plaintexts offline or fingerprint identical plaintexts across separately-encrypted files.
Risk Assessment
Exposure of plaintext hashes may allow guessing the content of encrypted data, compromising confidentiality.
Recommendation
Upgrade openssl_encrypt to version 1.4.9 or later, which no longer stores this hash in the header.
Original NVD description (English source)
openssl_encrypt versions before 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file header metadata. Attackers can read this hash without the password to confirm guessed plaintexts offline or fingerprint identical plaintexts across separately-encrypted files.