Gnutls: gnutls: security bypass allows acceptance of revoked server certificates via crafted ocsp response

Summary

A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted Online Certificate Status Protocol (OCSP) response during a TLS handshake. Due to a logic error in how gnutls processes multi-record OCSP responses, a client with OCSP verification enabled may incorrectly accept a revoked server certificate, potentially leading to a compromise of trust.

Timeline

1. Apr 30, 2026, 5:41 PM UTCCVE published
2. Apr 30, 2026, 6:22 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: partial

3. Oct 14, 2026, 7:45 PM UTCRecord last updated

Affected versions

• gnutls

  fixed in 3.8.13

• gnutls

  Version range not reported

• gnutls

  Version range not reported

• gnutls

  Version range not reported

• cert-manager/jetstack-cert-manager-acmesolver-rhel9

  Version range not reported

• cert-manager/jetstack-cert-manager-rhel9

  Version range not reported

• cert-manager/cert-manager-operator-rhel9

  Version range not reported

• cert-manager/cert-manager-operator-bundle

  Version range not reported

• cert-manager/jetstack-cert-manager-acmesolver-rhel9

  Version range not reported

• cert-manager/jetstack-cert-manager-rhel9

  Version range not reported

• cert-manager/cert-manager-istio-csr-rhel9

  Version range not reported

• cert-manager/cert-manager-operator-rhel9

  Version range not reported

• cert-manager/cert-manager-operator-bundle

  Version range not reported

• cert-manager/cert-manager-trust-manager-rhel9

  Version range not reported

• discovery/discovery-server-rhel9

  Version range not reported

• discovery/discovery-ui-rhel9

  Version range not reported

• gnutls-main

  Version range not reported

• rhui5/cds-rhel9

  Version range not reported

• rhui5/haproxy-rhel9

  Version range not reported

• rhui5/installer-rhel9

  Version range not reported

• rhui5/rhua-rhel9

  Version range not reported

• rhui5/cds-kubernetes-tp-rhel9

  Version range not reported

• rhui5/installer-tp-rhel9

  Version range not reported

• rhui5/rhua-tp-rhel9

  Version range not reported

• gnutls

  Version range not reported

• gnutls

  Version range not reported

• gnutls

  Version range not reported

• openshift4/ose-hypershift-rhel9

  Version range not reported

• openshift/ose-rhel-coreos-8

  Version range not reported

• openshift/ose-rhel-coreos-9

  Version range not reported

References 18