CVE-2026-3833
gnutls28: A flaw was found in gnutls
CVE-2026-3833 is fixed in 21 products on 1 platform, first by gnutls-bin 3.5.18-1ubuntu1.6+esm3, released May 4, 2026. It is not reported as exploited. Patch Radar priority: High.
High
CVSS
8.2
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0057
47th percentile
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.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| gnutls · RHEL 10 | 3.8.9-9.el10_0.19 | RHSA-2026:26409 | May 4, 2026 |
| gnutls · RHEL 8 | 0:3.6.16-8.el8_10.6 | RHSA-2026:20611 | May 27, 2026 |
| gnutls · RHEL 9 | 0:3.8.10-4.el9_8 | RHSA-2026:20612 | Jun 24, 2026 |
| gnutls · almalinux 10 | 3.8.10-4.el10_2 | ALSA-2026:20613 | May 26, 2026 |
| gnutls · almalinux 8 | 3.6.16-8.el8_10.6 | ALSA-2026:20611 | May 26, 2026 |
| gnutls · almalinux 9 | 3.8.10-4.el9_8 | ALSA-2026:20612 | May 26, 2026 |
| gnutls · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls · ol 10 | 0:3.8.10-4.el10_2 | ELSA-2026-20613 | Jul 17, 2026 |
| gnutls · ol 8 | 0:3.6.16-8.el8_10.6 | ELSA-2026-20611 | May 27, 2026 |
| gnutls · ol 9 | 0:3.8.10-4.el9_8 | ELSA-2026-20612 | Jun 24, 2026 |
| gnutls · rocky 10 | 0:3.8.10-4.el10_2 | RLSA-2026:20613 | Jun 5, 2026 |
| gnutls · rocky 8 | 0:3.6.16-8.el8_10.6 | RLSA-2026:20611 | May 29, 2026 |
| gnutls · rocky 9 | 0:3.8.10-4.el9_8 | RLSA-2026:20612 | Jun 2, 2026 |
| gnutls-bin · Ubuntu 18.04.6 LTS (bionic) | 3.5.18-1ubuntu1.6+esm3 | gnutls-bin 3.5.18-1ubuntu1.6+esm3 | May 4, 2026 |
| gnutls-bin · Ubuntu 20.04 LTS (focal) | 3.6.13-2ubuntu1.12+esm2 | gnutls-bin 3.6.13-2ubuntu1.12+esm2 | May 7, 2026 |
| gnutls-bin · Ubuntu 22.04.1 LTS (jammy) | 3.7.3-4ubuntu1.9 | gnutls-bin 3.7.3-4ubuntu1.9 | May 27, 2026 |
| gnutls-bin · Ubuntu 24.04.5 LTS (noble) | 3.8.3-1.1ubuntu3.6 | gnutls-bin 3.8.3-1.1ubuntu3.6 | May 27, 2026 |
| gnutls-bin · Ubuntu 25.10 (questing) | 3.8.9-3ubuntu2.2 | gnutls-bin 3.8.9-3ubuntu2.2 | May 27, 2026 |
| gnutls-bin · Ubuntu 26.04.1 LTS (resolute) | 3.8.12-2ubuntu1.1 | gnutls-bin 3.8.12-2ubuntu1.1 | May 7, 2026 |
| gnutls-c++ · RHEL 8 | 0:3.6.16-8.el8_10.6 | RHSA-2026:20611 | May 27, 2026 |
| gnutls-c++ · RHEL 9 | 0:3.8.10-4.el9_8 | RHSA-2026:20612 | Jun 24, 2026 |
| gnutls-c++ · almalinux 10 | 3.8.10-4.el10_2 | ALSA-2026:20613 | May 26, 2026 |
| gnutls-c++ · almalinux 8 | 3.6.16-8.el8_10.6 | ALSA-2026:20611 | May 26, 2026 |
| gnutls-c++ · almalinux 9 | 3.8.10-4.el9_8 | ALSA-2026:20612 | May 26, 2026 |
| gnutls-c++ · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-c++ · ol 10 | 0:3.8.10-4.el10_2 | ELSA-2026-20613 | Jul 17, 2026 |
| gnutls-c++ · ol 8 | 0:3.6.16-8.el8_10.6 | ELSA-2026-20611 | May 27, 2026 |
| gnutls-c++ · ol 9 | 0:3.8.10-4.el9_8 | ELSA-2026-20612 | Jun 24, 2026 |
| gnutls-c++-debuginfo · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-dane · RHEL 8 | 0:3.6.16-8.el8_10.6 | RHSA-2026:20611 | May 27, 2026 |
| gnutls-dane · RHEL 9 | 0:3.8.10-4.el9_8 | RHSA-2026:20612 | Jun 24, 2026 |
| gnutls-dane · almalinux 10 | 3.8.10-4.el10_2 | ALSA-2026:20613 | May 26, 2026 |
| gnutls-dane · almalinux 8 | 3.6.16-8.el8_10.6 | ALSA-2026:20611 | May 26, 2026 |
| gnutls-dane · almalinux 9 | 3.8.10-4.el9_8 | ALSA-2026:20612 | May 26, 2026 |
| gnutls-dane · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-dane · ol 10 | 0:3.8.10-4.el10_2 | ELSA-2026-20613 | Jul 17, 2026 |
| gnutls-dane · ol 8 | 0:3.6.16-8.el8_10.6 | ELSA-2026-20611 | May 27, 2026 |
| gnutls-dane · ol 9 | 0:3.8.10-4.el9_8 | ELSA-2026-20612 | Jun 24, 2026 |
| gnutls-dane-debuginfo · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-debuginfo · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-debugsource · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-devel · RHEL 8 | 0:3.6.16-8.el8_10.6 | RHSA-2026:20611 | May 27, 2026 |
| gnutls-devel · RHEL 9 | 0:3.8.10-4.el9_8 | RHSA-2026:20612 | Jun 24, 2026 |
| gnutls-devel · almalinux 10 | 3.8.10-4.el10_2 | ALSA-2026:20613 | May 26, 2026 |
| gnutls-devel · almalinux 8 | 3.6.16-8.el8_10.6 | ALSA-2026:20611 | May 26, 2026 |
| gnutls-devel · almalinux 9 | 3.8.10-4.el9_8 | ALSA-2026:20612 | May 26, 2026 |
| gnutls-devel · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-devel · ol 10 | 0:3.8.10-4.el10_2 | ELSA-2026-20613 | Jul 17, 2026 |
| gnutls-devel · ol 8 | 0:3.6.16-8.el8_10.6 | ELSA-2026-20611 | May 27, 2026 |
| gnutls-devel · ol 9 | 0:3.8.10-4.el9_8 | ELSA-2026-20612 | Jun 24, 2026 |
| gnutls-fips · almalinux 10 | 3.8.10-4.el10_2 | ALSA-2026:20613 | May 26, 2026 |
| gnutls-fips · ol 10 | 0:3.8.10-4.el10_2 | ELSA-2026-20613 | Jul 17, 2026 |
| gnutls-utils · RHEL 8 | 0:3.6.16-8.el8_10.6 | RHSA-2026:20611 | May 27, 2026 |
| gnutls-utils · RHEL 9 | 0:3.8.10-4.el9_8 | RHSA-2026:20612 | Jun 24, 2026 |
| gnutls-utils · almalinux 10 | 3.8.10-4.el10_2 | ALSA-2026:20613 | May 26, 2026 |
| gnutls-utils · almalinux 8 | 3.6.16-8.el8_10.6 | ALSA-2026:20611 | May 26, 2026 |
| gnutls-utils · almalinux 9 | 3.8.10-4.el9_8 | ALSA-2026:20612 | May 26, 2026 |
| gnutls-utils · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls-utils · ol 10 | 0:3.8.10-4.el10_2 | ELSA-2026-20613 | Jul 17, 2026 |
| gnutls-utils · ol 8 | 0:3.6.16-8.el8_10.6 | ELSA-2026-20611 | May 27, 2026 |
| gnutls-utils · ol 9 | 0:3.8.10-4.el9_8 | ELSA-2026-20612 | Jun 24, 2026 |
| gnutls-utils-debuginfo · amzn 2023 | 3.8.3-8.amzn2023.0.3 | ALAS2023-2026-1757 | May 25, 2026 |
| gnutls28 · Debian 12.15 (bookworm) | 3.7.9-2+deb12u7 | DEBIAN-CVE-2026-3833 | May 15, 2026 |
| gnutls28 · Debian 13.5 (trixie) | 3.8.9-3+deb13u4 | DEBIAN-CVE-2026-3833 | May 15, 2026 |
| gnutls28 · Debian 14 | 3.8.13-1 | DEBIAN-CVE-2026-3833 | May 15, 2026 |
| guile-gnutls · Ubuntu 20.04 LTS (focal) | 3.6.13-2ubuntu1.12+esm2 | guile-gnutls 3.6.13-2ubuntu1.12+esm2 | May 7, 2026 |
| guile-gnutls · Ubuntu 22.04.1 LTS (jammy) | 3.7.3-4ubuntu1.9 | guile-gnutls 3.7.3-4ubuntu1.9 | May 27, 2026 |
| libgnutls-dane0 · Ubuntu 18.04.6 LTS (bionic) | 3.5.18-1ubuntu1.6+esm3 | libgnutls-dane0 3.5.18-1ubuntu1.6+esm3 | May 4, 2026 |
| libgnutls-dane0 · Ubuntu 20.04 LTS (focal) | 3.6.13-2ubuntu1.12+esm2 | libgnutls-dane0 3.6.13-2ubuntu1.12+esm2 | May 7, 2026 |
| libgnutls-dane0 · Ubuntu 22.04.1 LTS (jammy) | 3.7.3-4ubuntu1.9 | libgnutls-dane0 3.7.3-4ubuntu1.9 | May 27, 2026 |
| libgnutls-dane0t64 · Ubuntu 24.04.5 LTS (noble) | 3.8.3-1.1ubuntu3.6 | libgnutls-dane0t64 3.8.3-1.1ubuntu3.6 | May 27, 2026 |
| libgnutls-dane0t64 · Ubuntu 25.10 (questing) | 3.8.9-3ubuntu2.2 | libgnutls-dane0t64 3.8.9-3ubuntu2.2 | May 27, 2026 |
| libgnutls-dane0t64 · Ubuntu 26.04.1 LTS (resolute) | 3.8.12-2ubuntu1.1 | libgnutls-dane0t64 3.8.12-2ubuntu1.1 | May 7, 2026 |
| libgnutls-openssl27 · Ubuntu 18.04.6 LTS (bionic) | 3.5.18-1ubuntu1.6+esm3 | libgnutls-openssl27 3.5.18-1ubuntu1.6+esm3 | May 4, 2026 |
| libgnutls-openssl27 · Ubuntu 20.04 LTS (focal) | 3.6.13-2ubuntu1.12+esm2 | libgnutls-openssl27 3.6.13-2ubuntu1.12+esm2 | May 7, 2026 |
| libgnutls-openssl27 · Ubuntu 22.04.1 LTS (jammy) | 3.7.3-4ubuntu1.9 | libgnutls-openssl27 3.7.3-4ubuntu1.9 | May 27, 2026 |
| libgnutls-openssl27t64 · Ubuntu 24.04.5 LTS (noble) | 3.8.3-1.1ubuntu3.6 | libgnutls-openssl27t64 3.8.3-1.1ubuntu3.6 | May 27, 2026 |
| libgnutls-openssl27t64 · Ubuntu 25.10 (questing) | 3.8.9-3ubuntu2.2 | libgnutls-openssl27t64 3.8.9-3ubuntu2.2 | May 27, 2026 |
| libgnutls-openssl27t64 · Ubuntu 26.04.1 LTS (resolute) | 3.8.12-2ubuntu1.1 | libgnutls-openssl27t64 3.8.12-2ubuntu1.1 | May 7, 2026 |
| libgnutls30 · Ubuntu 18.04.6 LTS (bionic) | 3.5.18-1ubuntu1.6+esm3 | libgnutls30 3.5.18-1ubuntu1.6+esm3 | May 4, 2026 |
| libgnutls30 · Ubuntu 20.04 LTS (focal) | 3.6.13-2ubuntu1.12+esm2 | libgnutls30 3.6.13-2ubuntu1.12+esm2 | May 7, 2026 |
| libgnutls30 · Ubuntu 22.04.1 LTS (jammy) | 3.7.3-4ubuntu1.9 | libgnutls30 3.7.3-4ubuntu1.9 | May 27, 2026 |
| libgnutls30t64 · Ubuntu 24.04.5 LTS (noble) | 3.8.3-1.1ubuntu3.6 | libgnutls30t64 3.8.3-1.1ubuntu3.6 | May 27, 2026 |
| libgnutls30t64 · Ubuntu 25.10 (questing) | 3.8.9-3ubuntu2.2 | libgnutls30t64 3.8.9-3ubuntu2.2 | May 27, 2026 |
| libgnutls30t64 · Ubuntu 26.04.1 LTS (resolute) | 3.8.12-2ubuntu1.1 | libgnutls30t64 3.8.12-2ubuntu1.1 | May 7, 2026 |
| libgnutlsxx28 · Ubuntu 18.04.6 LTS (bionic) | 3.5.18-1ubuntu1.6+esm3 | libgnutlsxx28 3.5.18-1ubuntu1.6+esm3 | May 4, 2026 |
| libgnutlsxx28 · Ubuntu 20.04 LTS (focal) | 3.6.13-2ubuntu1.12+esm2 | libgnutlsxx28 3.6.13-2ubuntu1.12+esm2 | May 7, 2026 |
| libgnutlsxx28 · Ubuntu 22.04.1 LTS (jammy) | 3.7.3-4ubuntu1.9 | libgnutlsxx28 3.7.3-4ubuntu1.9 | May 27, 2026 |
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