Libreswan Project up to 5.3.2/5.4.0 PKCS#7 SEC_PKCS7GetCertificateList null pointer dereference

Summaryinfo

A vulnerability identified as critical has been detected in Libreswan Project Libreswan up to 5.3.2/5.4.0. Affected by this issue is the function SEC_PKCS7GetCertificateList of the component PKCS#7 Handler. This manipulation causes null pointer dereference. This vulnerability is handled as CVE-2026-77207. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Libreswan Project Libreswan up to 5.3.2/5.4.0 and classified as critical. Affected by this vulnerability is the function SEC_PKCS7GetCertificateList of the component PKCS#7 Handler. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at libreswan.org. This vulnerability is known as CVE-2026-77207 since 08/20/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available.

Upgrading to version 5.3.3 or 5.4.1 eliminates this vulnerability.

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Productinfo

Type

• Project Management Software

Vendor

• Libreswan Project

Name

• Libreswan

Version

• 5.0
• 5.1
• 5.2
• 5.3
• 5.3.0
• 5.3.1
• 5.3.2
• 5.4.0

CPE 2.3info

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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