CVE-2026-77207Null Pointer Dereference in PKCS#7 bundle with no certificates
- 7.5HighCVSS base score
- 0.46%Exploitation in 30 daysEPSS · top 59% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By libreswan
- 54 days later
· 54 days later
Published
- 3 days later
· 3 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| libreswanCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.46% · top 59% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
The Libreswan Project · libreswan
- affected 4.7 – ≤ 5.3.2
- affected 5.4 – ≤ 5.4
- unaffected 5.3.3
- unaffected 5.4.1
What to do
Solution: Upgrade to libreswan 5.3.3 or 5.4.1 or later. Patches are available at https://libreswan.org/security/CVE-2026-77207/
Workaround: Apply the available patch or upgrade to a supported version. No configuration-based workaround is available.
Exploitation: No known exploitation in the wild. Exploitation requires sending a malicious IKE CERT payload with a PKCS#7 SignedData containing a CRL but no certificates, and does not require peer authentication.
References
References2
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-100749 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-77207)Record last updated .