PT-2026-55314 · Libreswan · Libreswan

Hu Xinyao · Published 2026-07-02 · Updated 2026-07-03 · CVE-2026-12413

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Libreswan (affected versions not specified)

Description An invalidly formatted IKEv2 fragment can cause the pluto daemon to crash and restart, leading to a denial of service. The issue occurs within the reassemble v2 incoming fragments() function, which ignores unknown outer payloads but stores them 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)) triggers the daemon to abort. This affects any configuration allowing IKEv2 connections where fragmentation=no is not set. Remote code execution is not possible.

Recommendations As a temporary mitigation, set fragmentation=no in the configuration to disable IKEv2 fragmentation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

RCE

Assertion Failure

Weakness Enumeration

CWE-193

CWE-617

Related Identifiers

CVE-2026-12413

Affected Products

Libreswan

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2026-12413 · Security Note
• https://twitter.com/infoflowcloud/status/2072815449268437019 · Twitter Post
• https://twitter.com/CVEnew/status/2072814571308687757 · Twitter Post
• https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt · Note
• https://libreswan.org/security/CVE-2026-12413 · Note
• https://twitter.com/UpwindMDR/status/2072943273866387821 · Twitter Post