OCSP Response Handling Vulnerability in Botan Cryptography Library

CVE-2026-118768

What is CVE-2026-118768?

The Botan cryptography library has a serious flaw in its OCSP response handling. From versions 1.11.34 to 3.12.0, the botan ocsp_check command fetches OCSP responses from a certificate's Authority Information Access URL without properly verifying the response signature or authorizing the signer. This oversight may allow a malicious responder or an on-path attacker to return a seemingly valid good response with an empty or unauthorized signature. Consequently, this can lead to a revoked certificate being incorrectly recognized as valid, resulting in misleading exit statuses from the OCSP check. The issue is resolved in version 3.13.0.

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