RHSA-2026:89923HighCVSS 7.5

Red Hat Security Advisory: libreswan security update

Published
October 26, 2026
Last Modified
October 26, 2026

🔗 CVE IDs covered (3)

CVE-2026-77205 →CVE-2026-77207 →CVE-2026-94453 →

📋 Description

CVE-2026-77205 — libreswan: Denial of Service via sending bogus X.509 certificates CVE-2026-77207 — libreswan: Null Pointer Dereference in PKCS#7 bundle with no CERTS CVE-2026-94453 — libreswan: IKEv2 Use-After-Free bug when using IKE-over-TCP

🎯 Affected products18

  • Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-0:5.3.3-1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-0:5.3.3-1.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-0:5.3.3-1.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-0:5.3.3-1.el10_2.src as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-0:5.3.3-1.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-debugsource-0:5.3.3-1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-debugsource-0:5.3.3-1.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-debugsource-0:5.3.3-1.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-debugsource-0:5.3.3-1.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-0:5.3.3-1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-0:5.3.3-1.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-0:5.3.3-1.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-0:5.3.3-1.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-debuginfo-0:5.3.3-1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-debuginfo-0:5.3.3-1.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-debuginfo-0:5.3.3-1.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • libreswan-minimal-debuginfo-0:5.3.3-1.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: Disabling FIPS mode will prevent this attack vector. However, disabling FIPS mode may violate security or compliance requirements and should not be used as a workaround without authorization. Workaround: Red Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when/if they become available. Workaround: If IKE-over-TCP is not required, administrators can temporarily mitigate this vulnerability by setting `listen-tcp=no` in the Libreswan configuration. This disables the vulnerable IKE-over-TCP functionality. If IKE-over-TCP is required, administrators should restrict access to the listener to trusted peers where practical and apply the appropriate security update once available.

🔗 References (6)