NULL Pointer Dereference Affecting libreswan package, versions *


Severity

Recommended
medium

Based on CentOS security rating.

Threat Intelligence

EPSS
0.34% (26th percentile)

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  • Snyk IDSNYK-CENTOS8-LIBRESWAN-21018719
  • published16 Oct 2026
  • disclosed5 Oct 2026

Introduced: 5 Oct 2026

NewCVE-2026-77207  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for Centos:8 libreswan.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libreswan package and not the libreswan package as distributed by Centos. See How to fix? for Centos:8 relevant fixed versions and status.

Libreswan has a null pointer dereference bug in the PKCS#7 handling code for IKE certificate authentication. When libreswan decodes an IKE CERT payload of type CERT_PKCS7_WRAPPED_X509, it guards the PKCS#7 blob with SEC_PKCS7ContainsCertsOrCrls() and then iterates the certificate list with SEC_PKCS7GetCertificateList(). The two NSS APIs disagree on a SignedData that carries a CRL but no certificates: ContainsCertsOrCrls() returns PR_TRUE (there is a CRL), so the guard passes, but GetCertificateList() returns NULL (there are no certificates). This causes libreswan to dereference a null pointer leading to a crash and restart. A malicious IKE_AUTH packet can trigger this bug, meaning the peer does not need to be authenticated. No remote code execution is possible. Continued exploitation can cause a denial of service.

CVSS Base Scores

version 3.1