Libreswan 4.6 < 5.3.1 DoS

high Nessus Plugin ID 327416

Synopsis

The version of Libreswan installed on the remote host is affected by a denial of service vulnerability.

Description

The version of Libreswan installed on the remote host is between 4.6 and 5.3.1 (exclusive). It is, therefore, affected by a denial of service vulnerability. An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. 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 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.

Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Libreswan version 5.3.1 or later.

Plugin Details

Severity: High

ID: 327416

File Name: libreswan_CVE-2026-12413.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 7/16/2026

Updated: 7/16/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.8

CVSS v2

Risk Factor: High

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-12413

CVSS v3

Risk Factor: High

Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Vulnerability Information

CPE: cpe:/a:libreswan:libreswan

Required KB Items: installed_sw/Libreswan

Patch Publication Date: 6/24/2026

Vulnerability Publication Date: 6/24/2026

Reference Information

CVE: CVE-2026-12413

Detections

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