CVE-2026-81680: openssl_encrypt before 1.4.9 Authentication Bypass via Recovery Slot Removal
opensslencrypt versions before 1.4.9 fail to authenticate recovery-slot presence in envelope-format encrypted files, allowing attackers to remove recovery slots without re-encrypting the payload. Attackers can modify the file header to delete recovery-slot fields and bypass authentication, silently removing recovery paths the owner deliberately added.
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 - Compensating control
For envelope-format encrypted files, ensure recovery-slot fields are present and cannot be removed without re-encrypting the payload (validate recovery-slot presence as part of authentication/recovery handling).
Event History
Frequently Asked Questions
Which files are exposed to this issue?
Envelope-format encrypted files that include recovery slots are affected when processed by openssl_encrypt versions before 1.4.9. Files without recovery slots are not described as affected.
What access does an attacker need?
An attacker needs the ability to modify the encrypted file header. No credentials or user interaction are required according to the supplied severity vector.
How can I determine whether I am already affected?
Check whether your openssl_encrypt version is earlier than 1.4.9 and identify envelope-format encrypted files containing recovery-slot fields. Such files may have had those fields removed without re-encrypting the payload.
What should be done if recovery access is important?
Use version 1.4.9 or later, since the issue affects versions before 1.4.9. Review affected encrypted files to confirm that expected recovery-slot fields are still present.