CVE-2026-3833

MEDIUM

6.5

CVSS v3

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.

CWE-178

How to fix

Remediation Available

gnutls28Debian

Fixed in:3.7.1-5+deb11u10CVE-2026-3833

Fixed in:3.7.9-2+deb12u7CVE-2026-3833

Fixed in:3.8.9-3+deb13u4CVE-2026-3833

Fixed in:3.8.13-1CVE-2026-3833

gnutlsRocky

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutlsRed Hat / RHEL

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-c++Rocky

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-c++Red Hat / RHEL

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-c++-debuginfoRed Hat / RHEL

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-c++-debuginfoRocky

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-daneRocky

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-daneRed Hat / RHEL

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-dane-debuginfoRocky

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-dane-debuginfoRed Hat / RHEL

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-debuginfoRed Hat / RHEL

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-debuginfoRocky

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-debugsourceRed Hat / RHEL

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-debugsourceRocky

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-develRed Hat / RHEL

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-develRocky

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-fipsRocky

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-fipsRed Hat / RHEL

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

gnutls-utilsRed Hat / RHEL

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-utilsRocky

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-utils-debuginfoRed Hat / RHEL

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

gnutls-utils-debuginfoRocky

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409

Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613

libtasn1Red Hat / RHEL

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

libtasn1Rocky

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

libtasn1-debuginfoRed Hat / RHEL

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

libtasn1-debuginfoRocky

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

libtasn1-debugsourceRed Hat / RHEL

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

libtasn1-debugsourceRocky

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

libtasn1-develRed Hat / RHEL

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-3.el8_6.2RHSA-2026:30849

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

Fixed in:0:4.13-3.el8_4.1RHSA-2026:33125

Fixed in:0:4.13-4.el8_8.1RHSA-2026:30850

This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Exploit Intelligence

0.56%probability of exploitation in 30 days

45thpercentile

Moderate risk: more likely to be exploited than 45% of all known CVEs.

References

Exploit1

gitlab.com

Third-Party Advisory3

Other references15

Related Vulnerabilities

Other CWE-178 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-27636	Medium	5.6	81%	-	Fix
CVE-2021-24347	High	8.8	54%	-	Fix
CVE-2020-12812	Critical	9.8	49%	KEV + Ransom	Fix
CVE-2003-0411	High	7.5	25%	-	-
CVE-2018-9845	Critical	9.8	13%	-	Fix
CVE-2001-0766	Critical	9.8	8.2%	-	-

Common questions

How do I fix CVE-2026-3833?

Published advisories record a fix for 65 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-3833 being actively exploited?

Not that we know of. CVE-2026-3833 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.56% is the estimated probability that it will be exploited in the next 30 days. That is higher than 45% of all scored CVEs.

How severe is CVE-2026-3833?

CVE-2026-3833 has a CVSS v3 base score of 6.5, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-3833 affect?

Published advisories record a fix for gnutls28 (Debian), gnutls (Rocky), gnutls (Red Hat / RHEL), gnutls-c++ (Rocky), and 61 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-3833

Markdown

[![CVE-2026-3833](https://tridentstack.com/cve/badge/CVE-2026-3833.svg)](https://tridentstack.com/cve/CVE-2026-3833)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-3833"><img src="https://tridentstack.com/cve/badge/CVE-2026-3833.svg" alt="CVE-2026-3833"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it works Start freeThis CVE lookup is free and always will be.

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-26.