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.

Project Subscriptions

Vendors Products
Libreswan Subscribe
Libreswan Subscribe
Advisories

No advisories yet.

Fixes

Solution

Upgrade to libreswan 5.3.1 or later. Patches for libreswan 4.15 and 5.3 are available at https://libreswan.org


Workaround

If fragmentation is not needed, fragmentation=no can be added to all IKEv2 configurations. If fragmentation is needed, no workaround is possible and the fix needs to be applied.

History

Wed, 15 Jul 2026 00:15:00 +0000


Tue, 07 Jul 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 06 Jul 2026 23:15:00 +0000

Type Values Removed Values Added
First Time appeared Libreswan
Libreswan libreswan
Vendors & Products Libreswan
Libreswan libreswan

Thu, 02 Jul 2026 21:45:00 +0000

Type Values Removed Values Added
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.
Title IKEv2 Denial of Service via malformed fragmentation
Weaknesses CWE-193
CWE-617
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: libreswan

Published:

Updated: 2026-07-07T17:02:12.976Z

Reserved: 2026-06-16T15:52:12.674Z

Link: CVE-2026-12413

cve-icon Vulnrichment

Updated: 2026-07-06T18:12:22.546Z

cve-icon NVD

No data.

cve-icon Redhat

Severity : Important

Publid Date: 2026-06-24T00:00:00Z

Links: CVE-2026-12413 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-26T23:15:05Z

Weaknesses