IKEv2 Denial of Service via malformed fragmentation (CVE-2026-12413) | HOL Guard CVE

High · CVSS 7.5CVE-2026-12413

IKEv2 Denial of Service via malformed fragmentation

Answer in brief

CVE-2026-12413 records a High severity (CVSS 7.5) vulnerability in IKEv2 Denial of Service via malformed fragmentation. The current sources do not mark it as known exploited. The current feed maps The Libreswan Project/libreswan (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 2, 2026Updated Jul 8, 2026Source checked Sep 22, 2026First seen by HOL Jul 2, 2026Material review Jul 8, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps The Libreswan Project/libreswan (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
The Libreswan Project/libreswangeneric	4.6	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for The Libreswan Project/libreswan.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Jul 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 2, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.