CVE-2026-12413

IKEv2 Denial of Service via malformed fragmentation

HIGH
7.5
CVSS Score
Published: July 2, 2026 at 09:19 PM UTC
Updated: October 25, 2026 at 09:10 PM UTC
1 product affected across 1 vendorLibreswan

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
No known 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.6 ≤ v < 5.3.14.6
Vendor states this is fixed in 5.3.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Vendor Advisory
Source: cverecord
https://libreswan.org/security/CVE-2026-12413/

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHlibreswan
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-193CWE-617

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