CVE-2026-81718: openssl_encrypt before 1.4.9 Weak Cryptographic Parameters
opensslencrypt versions before 1.4.9 use under-parameterized PBKDF2-HMAC-SHA256 with only 100,000 iterations to protect PQC keyfile private keys and 10,000 iterations for dual-encryption file-password verification. Attackers who obtain keyfiles or encrypted files can brute-force wrapping passwords offline using GPU or ASIC acceleration.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
openssl_encryptto a version that resolves this vulnerability.Fixed in 1.4.9
Event History
Frequently Asked Questions
Who is realistically exposed to password-cracking attacks?
Organizations or users whose PQC keyfiles or encrypted files were created with affected versions and could be obtained by an attacker are exposed. The attack is offline, so an attacker does not need access to a running service after acquiring the protected files.
What does an attacker need to exploit this issue?
An attacker needs a copy of an affected keyfile or encrypted file and can then attempt to brute-force its wrapping password offline using GPU or ASIC acceleration. No privileges or user interaction are required according to the supplied severity vector.
Are files created before upgrading still at risk?
The data identifies weak PBKDF2-HMAC-SHA256 iteration counts in versions before 1.4.9, but does not state that upgrading changes protection for files already created. Treat previously generated keyfiles and encrypted files as potentially susceptible if an attacker may have obtained them.