Vulnerability Details CVE-2026-3833
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 31.9%
CVSS Severity
CVSS v3 Score 6.5
References
- https://access.redhat.com/errata/RHSA-2026:13274
- https://access.redhat.com/errata/RHSA-2026:20611
- https://access.redhat.com/errata/RHSA-2026:20612
- https://access.redhat.com/errata/RHSA-2026:20613
- https://access.redhat.com/security/cve/CVE-2026-3833
- https://bugzilla.redhat.com/show_bug.cgi?id=2445763
- https://gitlab.com/gnutls/gnutls/-/issues/1803
- https://gitlab.com/gnutls/gnutls/-/issues/1803
Products affected by CVE-2026-3833
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cpe:2.3:a:gnu:gnutls:-
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cpe:2.3:a:redhat:hardened_images:-
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cpe:2.3:a:redhat:openshift_container_platform:4.0
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cpe:2.3:o:redhat:enterprise_linux:10.0
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cpe:2.3:o:redhat:enterprise_linux:6.0
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cpe:2.3:o:redhat:enterprise_linux:7.0
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cpe:2.3:o:redhat:enterprise_linux:8.0
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cpe:2.3:o:redhat:enterprise_linux:9.0