CVE-2026-12413
IKEv2 Denial of Service via malformed fragmentation
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.
INFO
Published Date :
July 2, 2026, 10:16 p.m.
Last Modified :
July 8, 2026, 6:52 p.m.
Remotely Exploit :
Yes !
Source :
d42dc95b-23f1-4e06-9076-20753a0fb0df
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | d42dc95b-23f1-4e06-9076-20753a0fb0df |
Solution
- Configure fragmentation=no for IKEv2 connections.
- Update Libreswan to the latest version.
- Restart the pluto daemon after applying changes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-12413.
| URL | Resource |
|---|---|
| https://libreswan.org/security/CVE-2026-12413/ | Vendor Advisory |
| https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt | Vendor Advisory Mitigation |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-12413 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-12413
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-12413 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-12413 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:libreswan:libreswan:*:*:*:*:*:*:*:* versions from (including) 4.6 up to (excluding) 5.3.1 Added Reference Type Libreswan Project: https://libreswan.org/security/CVE-2026-12413/ Types: Vendor Advisory Added Reference Type Libreswan Project: https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt Types: Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 07, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-12413', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-06T18:12:21.499364Z'} -
New CVE Received by d42dc95b-23f1-4e06-9076-20753a0fb0df
Jul. 02, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'The Libreswan Project', 'product': 'libreswan', 'versions': [{'status': 'affected', 'version': '4.6', 'versionType': 'semver', 'lessThanOrEqual': '5.3'}, {'status': 'unaffected', 'version': '5.3.1', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-193 Added CWE CWE-617 Added Reference https://libreswan.org/security/CVE-2026-12413/ Added Reference https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt