CVE-2026-3833
7.4
HIGH
CVSS 3.1
EPSS 0.13%
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.
How to fix CVE-2026-3833
To remediate CVE-2026-3833, upgrade the affected package to a fixed version below.
- —upgrade to 3.8.13-r0 or later
- —upgrade to 3.7.1-5+deb11u10 or later
Is CVE-2026-3833 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 3.8.13-r0
- from 0, < 3.7.1-5+deb11u10
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |