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Fencer Vulns
high 7.5

CVE-2026-94453 json

IKEv2 Use-After-Free bug when using IKE-over-TCP

published 2026-10-13 26 d ago modified 2026-10-16 23 d ago also EUVD-2026-100744

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

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 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.

Patch / fix

  • The Libreswan Project libreswan 5.3.3, 5.4.1
  • libreswan AlmaLinux 9 4.15-11.el9_8
  • libreswan AlmaLinux 10 5.3.3-1.el10_2
  • libreswan-minimal AlmaLinux 10 5.3.3-1.el10_2
  • libreswan AlmaLinux 8 4.12-2.el8_10.7

almalinux advisories ALSA-2026:89748ALSA-2026:89923ALSA-2026:90492

  • libreswan Rocky Linux 8 4.12-2.el8_10.7
  • libreswan Rocky Linux 10 5.3.3-1.el10_2
  • libreswan Rocky Linux 9 4.15-11.el9_8

rocky linux advisories RLSA-2026:90492RLSA-2026:89923RLSA-2026:89748

  • libreswan Alpine 3.24, Alpine 3.23 5.3.3-r0

alpine advisories ALPINE-CVE-2026-94453

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libreswan Azure Linux 3.0 4.15-4

azure linux advisories AZL-108027

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-94453 updated cvss 7.5

libreswan: IKEv2 Use-After-Free bug when using IKE-over-TCP

  • Red Hat Fast Datapath for RHEL 9 libreswan
    affected: workaround, no fix available
  • Red Hat Enterprise Linux 6 libreswan
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 libreswan Red Hat OpenShift Container Platform 4 libreswan Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 8) libreswan 4.12-2.el8_10.7
    fixed: vendor fix RHSA-2026:90492
  • Red Hat Enterprise Linux AppStream (v. 9) libreswan 4.15-11.el9_8
    fixed: vendor fix RHSA-2026:89748
  • Red Hat Enterprise Linux AppStream (v. 10) libreswan 5.3.3-1.el10_2, libreswan-minimal 5.3.3-1.el10_2
    fixed: vendor fix RHSA-2026:89923
  • Red Hat OpenShift Container Platform 4.22 rhcos 4.22.9.8.202611032353
    fixed: vendor fix RHSA-2026:95346

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
23 d ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • The Libreswan Project libreswan

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.