Vulnerability in Libreswan
CVE-2026-12413
An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these 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)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Libreswan
- The Libreswan Project — versions 4.6, 5.3.1
Weakness classification (CWE)
References
- d42dc95b-23f1-4e06-9076-20753a0fb0df (Mitigation, Vendor Advisory)
- d42dc95b-23f1-4e06-9076-20753a0fb0df (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-12413?
- CVE-2026-12413 is a high-severity vulnerability in Libreswan, classified under Off-by-one Error. CVSS score: 7.5/10. Published 2026-07-02.
- How severe is CVE-2026-12413?
- High severity. CVSS v3 base score is 7.5 out of 10.