Red Hat Security Advisory: libreswan security update

Libreswan, a Linux implementation of IPsec and IKE protocols, contains several denial of service vulnerabilities: CVE-2026-50721 and CVE-2026-50722 allow DoS via RSA-SHA1 (PKCS#1 v1.5) authentication payloads in IKEv1 and IKEv2 respectively; CVE-2026-12413 allows DoS via malformed fragmentation in IKEv2; and CVE-2026-14957 causes an assertion failure and daemon crash when processing badly formatted X.509 certificates. These issues can disrupt VPN tunnel establishment or maintenance by crashing the libreswan daemon. Red Hat has issued a security advisory with updates for affected versions to remediate these vulnerabilities.

Successful exploitation of these vulnerabilities can cause denial of service conditions by crashing the libreswan daemon or disrupting IPsec VPN tunnels. This impacts the availability of secure network communications relying on libreswan. There is no indication of code execution or information disclosure. No known exploits are reported in the wild at this time.

Red Hat has released security updates for libreswan in Red Hat Enterprise Linux 9.6 Extended Update Support and related distributions. Users should apply the official patches provided by Red Hat as detailed in the advisory (https://access.redhat.com/articles/11258) to remediate these vulnerabilities. No additional mitigation steps are indicated by the vendor.