CVE-2026-81700: openssl_encrypt before 1.4.9 GPG Signature Verification Bypass
opensslencrypt versions before 1.4.9 contain a signature verification vulnerability in gpgrunner.verifydetached that accepts revoked and expired keys by only checking VALIDSIG status without inspecting REVKEYSIG, EXPKEYSIG, or gpg exit codes. Attackers holding compromised-then-revoked signing keys or expired project keys can bypass signature verification to execute malicious plugins in the host process.
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
Which deployments are exposed to exploitation?
Deployments using openssl_encrypt versions before 1.4.9 are exposed if they rely on gpg_runner.verify_detached to verify plugin signatures. The impact described is execution of malicious plugins in the host process.
What does an attacker need to bypass verification?
An attacker needs access to a signing key that was compromised and then revoked, or to an expired project signing key. They can use such a key because the affected verification logic accepts VALIDSIG status without rejecting REVKEYSIG or EXPKEYSIG results.
How can I determine whether my verification workflow is affected?
Check whether the installed openssl_encrypt version is earlier than 1.4.9 and whether plugin verification uses gpg_runner.verify_detached. Affected logic checks only for VALIDSIG and does not inspect REVKEYSIG, EXPKEYSIG, or the GPG exit code.