---
id: CVE-2026-14957
title: >-
  In FIPS mode, Libreswan's add_decoded_cert() function calls
  CERT_ExtractPublicKey() and asserts that the result is not NULL
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 …
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-252
  - CWE-617
vendor: The Libreswan Project
product: libreswan
affected:
  - libreswan >= 3.0 <= 5.3.1
published: '2026-09-02'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T15:44:20.970'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-14957'
references:
  - url: 'https://libreswan.org/security/CVE-2026-14957/'
    label: d42dc95b-23f1-4e06-9076-20753a0fb0df
  - url: 'https://libreswan.org/security/CVE-2026-14957/CVE-2026-14957.txt'
    label: d42dc95b-23f1-4e06-9076-20753a0fb0df
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-02T13:00:08.993590Z'
ingestedAt: '2026-09-12T16:29:42.611Z'
epss: 0.00468
epssPercentile: 0.37828
---

## Overview

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.

## Remediation

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