Bug 2550632

Summary: CVE-2026-77206 libreswan: IKEv2 pre-authentication Null Pointer deref in EAP code [fedora-all]
Product: [Fedora] Fedora Reporter: TEJ RATHI <trathi>
Component: libreswanAssignee: Paul Wouters <paul.wouters>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: dueno, paul.wouters, shebburn
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---Flags: fedora-admin-xmlrpc: mirror+
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["b405d429-21a6-4bd0-a7e9-a9e9cf7fb7e1"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2550256    

Description TEJ RATHI 2026-10-13 15:41:38 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

The Libreswan Project was informed of a Null Pointer Dereference bug in the EAP handling code for authentication that can result in a denial of service against the libreswan pluto daemon. 

As a result of inconsistency within the IKEv2 state machine code, a bug can be triggered by any IKEv2 connection, even if EAP is not configured at all. The bug results in a crash and restart. No remote code execution is possible. The error is caused by a fall-through error where it incorrectly dereferences ike->sa.st_eap which is NULL.

An malicious IKE_AUTH packet can trigger this bug, meaning the peer need not be authenticated. Continued attempts to use IKEv2 with such malicious payloads can cause a denial of service. No remote code execution is possible.

Vulnerable versions : 4.7 - 5.4
Not vulnerable      : 5.3.3, 5.4.1