CVE-2026-12413

Name of the Vulnerable Software and Affected Versions Libreswan (affected versions not specified)

Description An invalidly formatted IKEv2 fragment can cause the pluto daemon to crash and restart, leading to a denial of service. The issue occurs within the reassemble v2 incoming fragments() function, which ignores unknown outer payloads but stores them in a fixed-size array msg digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md->digest roof < elemsof(md->digest)) triggers the daemon to abort. This affects any configuration allowing IKEv2 connections where fragmentation=no is not set. Remote code execution is not possible.

Recommendations As a temporary mitigation, set fragmentation=no in the configuration to disable IKEv2 fragmentation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.