SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-12413

An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart.

HIGH 7.5EPSS 0.60%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.60% probability · 47th percentile
CISA KEV
Not listed
Weakness
CWE-193, CWE-617
Affected
libreswan/libreswan
Source
d42dc95b-23f1-4e06-9076-20753a0fb0df

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.