CVE-2026-67693GnuTLS v3.8.13 does not reject end-entity X.509 certificates that contain a contradictory combination of Key Usage (KU) and Extended Key…
- 3.7LowCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
GnuTLS v3.8.13 does not reject end-entity X.509 certificates that contain a contradictory combination of Key Usage (KU) and Extended Key Usage (EKU). NOTE: the Supplier does not consider this an actionable security vulnerability because of its "threat model doesn't consider attacks only possible by modifying anything within the trust boundary (private keys, trusted certificate authorities and their issued certificates including intermediate CAs, etc.)" policy.
Timeline
ID reserved
By mitre
- 2 months later
· 2 months later
Published
- 27 days later
· 27 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 |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Low3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVDNVD · Awaiting Analysis | 3.1 | Low3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.7.
Affected products
n/a
- affected n/a
References
References6
- https://gitlab.com/gnutls/gnutls/-/blob/3.8.13/lib/x509/verify.c#L1119-1178 (opens in a new tab)
- https://gist.github.com/lkloliver/6fbfc191bc6163942c8017551ac3f238 (opens in a new tab)
- https://gitlab.com/gnutls/gnutls/-/work_items/1642 (opens in a new tab)
- https://gitlab.com/gnutls/gnutls/-/work_items/1965 (opens in a new tab)
- https://gitlab.com/gnutls/gnutls/-/blob/e2169a87c7fb91935c2845088204b102baed4c5f/SECURITY.md (opens in a new tab)
- https://github.com/lkloliver/poc/tree/main/CVE-2026-67693 (opens in a new tab)
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-2026-95206 (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-2026-67693)Record last updated .