---
id: CVE-2026-94453
title: >-
  Libreswan's pluto daemon has a use-after-free vulnerability when a client
  connecting using IKE over TCP closes the connection and another packet
  (retransmit or malicious) is received for the same tuple
summary: >-
  Libreswan's pluto daemon has a use-after-free vulnerability when a client
  connecting using IKE over TCP closes the connection and another packet
  (retransmit or malicious) is received for the same tuple. IKE state is
  retained in memory af…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-416
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - fast_datapath_for_rhel 9
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
patched:
  - enterprise_linux_appstream_v_9
published: '2026-10-13'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:55:59.740'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-94453'
references:
  - url: 'https://libreswan.org/security/CVE-2026-94453/'
    label: d42dc95b-23f1-4e06-9076-20753a0fb0df
  - url: 'https://libreswan.org/security/CVE-2026-94453/CVE-2026-94453.txt'
    label: d42dc95b-23f1-4e06-9076-20753a0fb0df
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-94453.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-94453'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2550254'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-94453'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-94453'
  - url: >-
      https://libreswan.org/security/CVE-2026-94453/libreswan-5.3-CVE-2026-94453.patch
  - url: >-
      https://libreswan.org/security/CVE-2026-94453/libreswan-5.4-CVE-2026-94453.patch
  - url: 'https://access.redhat.com/errata/RHSA-2026:89748'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00454
epssPercentile: 0.39259
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T15:14:22.083231Z'
ingestedAt: '2026-10-13T23:03:54.751Z'
---

## Overview

Libreswan's pluto daemon has a use-after-free vulnerability when a client connecting using IKE over TCP closes the connection and another packet (retransmit or malicious) is received for the same tuple. IKE state is retained in memory after the client closes the connection, storing a pointer to iface_endpoint inside ike_sa.sa->st_iface_endpoint. Once this invalid pointer is used, the daemon crashes and restarts. This vulnerability can be triggered before the remote peer has authenticated itself. Continued exploitation can lead to a denial of service. Remote code execution could be possible. The IKE over TCP option is not enabled by default; only configurations that contain listen-tcp=yes are affected.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Fast Datapath for RHEL 9, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Fast Datapath for RHEL 9, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, … · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-94453.json)
- **RHSA-2026:89748** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-10-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:89748)