CVE-2026-94453: CWE-416: Use After Free in The Libreswan Project libreswan
Description
Libreswan's pluto daemon contains a use-after-free vulnerability triggered when a client using IKE over TCP closes the connection and another packet is received for the same connection tuple. This causes the daemon to crash and restart, leading to denial of service. The vulnerability affects configurations with listen-tcp=yes enabled, which is not the default. Remote code execution may be possible. The flaw can be exploited before the remote peer authenticates.
CVSS v3.1
Score 7.5high
Affected software
The Libreswan Project
libreswan
pkg:github/libreswanRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-94453 is a use-after-free vulnerability in the Libreswan project's pluto daemon. It occurs when a client connecting via IKE over TCP closes the connection, but the daemon retains IKE state in memory, including a pointer to iface_endpoint inside ike_sa.sa->st_iface_endpoint. If a retransmitted or malicious packet arrives for the same tuple after closure, the daemon uses this invalid pointer, causing a crash and restart. The vulnerability can be triggered remotely without authentication and affects only configurations with listen-tcp=yes enabled. While denial of service is confirmed, remote code execution is considered possible but not confirmed.
Potential Impact
Exploitation causes the pluto daemon to crash and restart, resulting in denial of service. The vulnerability can be triggered remotely without authentication. Remote code execution is possible but not confirmed. The impact is limited to systems with IKE over TCP enabled (listen-tcp=yes).
Mitigation Recommendations
No official patch or fix information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. As a mitigation, disable the IKE over TCP option by ensuring listen-tcp is not enabled if it is not required. Monitor vendor advisories for patches or updates addressing this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- libreswan
- Date Reserved
- 2026-09-21T17:09:02.116Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6acea4042cdf04f656b3059f
Added to database: 10/13/2026, 21:35:00 UTC
Last enriched: 10/13/2026, 21:48:23 UTC
Last updated: 10/13/2026, 21:50:44 UTC
Views: 5
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