openssl_encrypt versions before 1.4.9 contain a weak key derivation vulnerability in the D-Bus CryptoService.EncryptFile handler that uses unstretched SHA-256 instead of Argon2id. Attackers can perform offline password guessing against encrypted files roughly six to seven orders of magnitude faster than documented protection by exploiting the missing key stretching and hash rounds.

openssl_encrypt versions prior to 1.4.9 contain a weak key derivation vulnerability in the D-Bus CryptoService.EncryptFile handler. The implementation uses unstretched SHA-256 instead of the recommended Argon2id algorithm for key derivation. This flaw allows attackers to perform offline password guessing attacks against encrypted files at speeds six to seven orders of magnitude faster than the documented protection level. The vulnerability stems from missing key stretching and hash rounds in the encryption pipeline. Exploitation requires access to encrypted files but no authentication or special privileges. Users are advised to upgrade to version 1.4.9 or later to mitigate the risk. The issue is tracked as CVE-2026-81704 and has been assigned a high criticality rating.