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Fencer Vulns
high 7.5

CVE-2026-77207 json

Null Pointer Dereference in PKCS#7 bundle with no certificates

published 2026-10-13 26 d ago modified 2026-10-16 23 d ago also EUVD-2026-100749

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

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.

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-2026-77207

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-108033

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-2026-77207 updated cvss 7.5

libreswan: Null Pointer Dereference in PKCS#7 bundle with no CERTS

  • Red Hat Fast Datapath for RHEL 9 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 Enterprise Linux 6 libreswan Red Hat Enterprise Linux 7 libreswan
    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
23 d ago

Exploit prediction

0.46% 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.