CVE-2026-14957 Affecting libreswan package, versions *


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.56% (45th percentile)

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  • Snyk IDSNYK-DEBIAN11-LIBRESWAN-18322084
  • published27 Jul 2026
  • disclosed2 Sept 2026

Introduced: 27 Jul 2026

CVE-2026-14957  (opens in a new tab)

How to fix?

There is no fixed version for Debian:11 libreswan.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libreswan package and not the libreswan package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1