Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication. As a result of inconsistency within the IKEv2 state machine code, this bug can be triggered by any IKEv2 connection, even if EAP is not configured at all. The error is caused by a fall-through where it incorrectly dereferences ike->sa.st_eap which is NULL. A malicious IKE_AUTH packet can trigger this bug, meaning the peer does not need to be authenticated. The bug results in a crash and restart of the pluto daemon. No remote code execution is possible. Continued exploitation can cause a denial of service.
History

Tue, 27 Oct 2026 04:30:00 +0000

Type Values Removed Values Added
First Time appeared Libreswan
Libreswan libreswan
Vendors & Products Libreswan
Libreswan libreswan

Sat, 17 Oct 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 14 Oct 2026 00:30:00 +0000


Tue, 13 Oct 2026 21:45:00 +0000

Type Values Removed Values Added
Description Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication. As a result of inconsistency within the IKEv2 state machine code, this bug can be triggered by any IKEv2 connection, even if EAP is not configured at all. The error is caused by a fall-through where it incorrectly dereferences ike->sa.st_eap which is NULL. A malicious IKE_AUTH packet can trigger this bug, meaning the peer does not need to be authenticated. The bug results in a crash and restart of the pluto daemon. No remote code execution is possible. Continued exploitation can cause a denial of service.
Title IKEv2 pre-authentication Null Pointer Dereference in EAP code
Weaknesses CWE-476
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: libreswan

Published: 2026-10-13T21:28:11.498Z

Updated: 2026-10-16T15:31:54.304Z

Reserved: 2026-08-20T18:13:09.377Z

Link: CVE-2026-77206

cve-icon Vulnrichment

Updated: 2026-10-16T15:30:06.811Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-13T22:18:24.727

Modified: 2026-10-16T19:55:59.740

Link: CVE-2026-77206

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-05T00:00:00Z

Links: CVE-2026-77206 - Bugzilla