CVE-2026-77207

A null pointer dereference flaw was found in Libreswan's PKCS#7 certificate payload handling. When processing a crafted IKEv2 IKE_AUTH packet containing a PKCS#7 bundle with a certificate revocation list but no certificates, Libreswan may dereference a null pointer, causing the pluto daemon to crash and restart. A remote, unauthenticated attacker could repeatedly trigger this flaw to cause a denial of service.

This vulnerability is rated as Moderate impact for Red Hat because exploitation requires Libreswan to be deployed, configured, and running as an IKEv2 endpoint, which is not the default configuration of a general-purpose Red Hat Enterprise Linux installation. A remote, unauthenticated attacker can send a crafted IKEv2 packet to crash the Libreswan daemon, potentially disrupting VPN connectivity. Although, systemd supervision typically restarts the crashed process automatically, reducing the persistence of service interruptions, repeated exploitation can cause continued denial of service.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

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.