Vulnerability Description
A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically for `dNSName` (DNS) or `rfc822Name` (email) constraints within `excludedSubtrees` or `permittedSubtrees`. A remote attacker can exploit this by crafting a leaf certificate with casing differences in the Subject Alternative Name (SAN), leading to a policy bypass where a certificate that should be rejected is instead accepted. This could result in unauthorized access or information disclosure.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Gnu | Gnutls | - |
| Redhat | Hardened Images | - |
| Redhat | Openshift Container Platform | 4.0 |
| Redhat | Enterprise Linux | 6.0 |
Related Weaknesses (CWE)
References
- https://access.redhat.com/errata/RHSA-2026:13274Issue TrackingThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2026-3833Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2445763Issue TrackingThird Party Advisory
- https://gitlab.com/gnutls/gnutls/-/issues/1803ExploitIssue TrackingVendor Advisory
- https://gitlab.com/gnutls/gnutls/-/issues/1803ExploitIssue TrackingVendor Advisory
FAQ
What is CVE-2026-3833?
CVE-2026-3833 is a vulnerability with a CVSS score of 6.5 (MEDIUM). A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically for `dNSName` (DNS) or `rfc822Name` (email) constrain...
How severe is CVE-2026-3833?
CVE-2026-3833 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-3833?
Check the references section above for vendor advisories and patch information. Affected products include: Gnu Gnutls, Redhat Hardened Images, Redhat Openshift Container Platform, Redhat Enterprise Linux.