CVE-2026-77207 Null Pointer Dereference in PKCS#7 bundle with no certificates
Unauthenticated remote attackers can crash Libreswan by sending a crafted IKE packet with a PKCS#7 payload containing only CRLs, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-77207?
CVE-2026-77207 is a high-severity vulnerability in The Libreswan Project libreswan, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-77207?
How do I fix CVE-2026-77207?
Apply the vendor's patch.
Is CVE-2026-77207 being exploited?
There is no known exploitation of CVE-2026-77207 in the wild and no public exploit code.
Sources
Also known as AZL-108033, CLSA-2026-1792158739, DEBIAN-CVE-2026-77207, GHSA-jf6r-wr9w-j67c.