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Fencer Vulns
high 7.5

CVE-2026-14957 json

FIPS mode assertion failure via malicious CERT payload

published 2026-09-02 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-69820

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 40%
public exploits
0
none known

Summary

In FIPS mode, Libreswan's add_decoded_cert() function calls CERT_ExtractPublicKey() and asserts that the result is not NULL. However, CERT_ExtractPublicKey() returns NULL when public key extraction fails, for example if the RSA exponent is set to 0. A remote attacker can send a malformed X.509 certificate in a CERT payload to trigger the assertion, causing the pluto daemon to abort and restart. Continued exploitation causes a denial of service. No remote code execution is possible. Both IKEv1 and IKEv2 are affected. The vulnerability is only exploitable when both the OS and libreswan are running in FIPS mode and at least one CA certificate is loaded. The CERT payload is processed before peer authentication, so no credentials are needed to exploit this. Configurations using only PreSharedKey (PSK) authentication with no CA certificates loaded in the NSS database are not vulnerable.

Patch / fix

  • The Libreswan Project libreswan 5.3.2
  • libreswan RHEL 9 5.3.2-1.el9fdp
  • libreswan RHEL 10.2 5.3.2-1.el10_2
  • libreswan-minimal RHEL 10.2 5.3.2-1.el10_2
  • libreswan RHEL 8 4.12-2.el8_10.6
  • libreswan RHEL 9 4.15-10.el9_8
  • libreswan RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.3-6.el8_4.2
  • libreswan RHEL 8.6 EUS_LONG_LIFE, RHEL 8.6 AUS 4.5-1.el8_6.6
  • libreswan RHEL 8.8 TUS, RHEL 8.8 E4S 4.9-3.el8_8.3

red hat advisories RHSA-2026:84887RHSA-2026:82154RHSA-2026:72287RHSA-2026:61779RHSA-2026:61258RHSA-2026:57741

  • libreswan AlmaLinux 8 4.12-2.el8_10.6
  • libreswan AlmaLinux 9 4.15-10.el9_8
  • libreswan AlmaLinux 10 5.3.2-1.el10_2
  • libreswan-minimal AlmaLinux 10 5.3.2-1.el10_2

almalinux advisories ALSA-2026:46396ALSA-2026:46397ALSA-2026:46398

  • libreswan Rocky Linux 10 5.3.2-1.el10_2
  • libreswan Rocky Linux 8 4.12-2.el8_10.6
  • libreswan Rocky Linux 9 4.15-10.el9_8

rocky linux advisories RLSA-2026:46398RLSA-2026:46396RLSA-2026:46397

  • libreswan Alpine 3.23 5.3.3-r0
  • libreswan Alpine 3.24 5.3.2-r0

alpine advisories ALPINE-CVE-2026-14957

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 4.15-3

azure linux advisories AZL-98441

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-2026-14957 updated cvss 7.5

libreswan: badly formatted X.509 certificate can cause an assertion failure that crashes the daemon process

  • 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 Fast Datapath for Red Hat Enterprise Linux 9 libreswan 5.3.2-1.el9fdp
    fixed: vendor fix RHSA-2026:46986
  • Red Hat Enterprise Linux AppStream (v. 8) libreswan 4.12-2.el8_10.6
    fixed: vendor fix RHSA-2026:46396
  • Red Hat Enterprise Linux AppStream (v. 9) libreswan 4.15-10.el9_8
    fixed: vendor fix RHSA-2026:46397
  • Red Hat Enterprise Linux AppStream (v. 10) libreswan 5.3.2-1.el10_2, libreswan-minimal 5.3.2-1.el10_2
    fixed: vendor fix RHSA-2026:46398
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) libreswan 4.3-6.el8_4.2
    fixed: vendor fix RHSA-2026:84887
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) libreswan 4.5-1.el8_6.6
    fixed: vendor fix RHSA-2026:82154
show 12 more
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) libreswan 4.9-3.el8_8.3
    fixed: vendor fix RHSA-2026:72287
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) libreswan 4.9-5.el9_2.5
    fixed: vendor fix RHSA-2026:61779
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) libreswan 4.12-3.el9_4.2
    fixed: vendor fix RHSA-2026:61258
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) libreswan 5.2-1.el10_0.5
    fixed: vendor fix RHSA-2026:55449
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) libreswan 4.15-8.el9_6.1
    fixed: vendor fix RHSA-2026:57741
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libreswan 4.3-6.el8_4.2
    fixed: vendor fix RHSA-2026:84887
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) libreswan 4.5-1.el8_6.6
    fixed: vendor fix RHSA-2026:82154
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) libreswan 4.9-3.el8_8.3
    fixed: vendor fix RHSA-2026:72287
  • Red Hat OpenShift Container Platform 4.19 rhcos 4.19.9.6.202609021231
    fixed: vendor fix RHSA-2026:63044
  • Red Hat OpenShift Container Platform 4.20 rhcos 4.20.9.6.202609021029
    fixed: vendor fix RHSA-2026:63100
  • Red Hat OpenShift Container Platform 4.21 rhcos 4.21.9.6.202609021100
    fixed: vendor fix RHSA-2026:63041
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) libreswan-debuginfo 4.3-6.el8_4.2, libreswan-debugsource 4.3-6.el8_4.2 Red Hat Enterprise Linux AppStream AUS (v.8.6) libreswan-debuginfo 4.5-1.el8_6.6, libreswan-debugsource 4.5-1.el8_6.6 Red Hat Enterprise Linux AppStream E4S (v.8.8) libreswan-debuginfo 4.9-3.el8_8.3, libreswan-debugsource 4.9-3.el8_8.3 Red Hat Enterprise Linux AppStream E4S (v.9.2) libreswan-debuginfo 4.9-5.el9_2.5, libreswan-debugsource 4.9-5.el9_2.5 Red Hat Enterprise Linux AppStream E4S (v.9.4) libreswan-debuginfo 4.12-3.el9_4.2, libreswan-debugsource 4.12-3.el9_4.2 Red Hat Enterprise Linux AppStream EUS (v. 10.0) libreswan-debuginfo 5.2-1.el10_0.5, libreswan-debugsource 5.2-1.el10_0.5
    +4 more products
    Red Hat Enterprise Linux AppStream EUS (v.9.6) libreswan-debuginfo 4.15-8.el9_6.1, libreswan-debugsource 4.15-8.el9_6.1 Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libreswan-debuginfo 4.3-6.el8_4.2, libreswan-debugsource 4.3-6.el8_4.2 Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) libreswan-debuginfo 4.5-1.el8_6.6, libreswan-debugsource 4.5-1.el8_6.6 Red Hat Enterprise Linux AppStream TUS (v.8.8) libreswan-debuginfo 4.9-3.el8_8.3, libreswan-debugsource 4.9-3.el8_8.3
    not affected: vulnerable code not present

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
2 mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.