PT-2026-36155 · Gnutls+3 · Gnutls+3

Oleh Konko · Published 2026-03-02 · Updated 2026-06-01 · CVE-2026-3833

Positive Technologies (AI Summary)

CVSS v3.1

7.4

High

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Name of the Vulnerable Software and Affected Versions gnutls (affected versions not specified)

Description A flaw exists where case-sensitive comparisons are performed on nameConstraints labels, specifically for dNSName (DNS) or rfc822Name (email) constraints within excludedSubtrees or permittedSubtrees. A remote attacker can craft a leaf certificate with casing differences in the Subject Alternative Name (SAN) to bypass policies, causing a certificate that should be rejected to be accepted. This may lead to unauthorized access or information disclosure.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Weakness Enumeration

CWE-178

Related Identifiers

ALSA-2026:20611

BDU:2026-07116

CVE-2026-3833

ECHO-EAAB-3ED4-9BFD

OESA-2026-2333

OESA-2026-2334

OESA-2026-2335

OESA-2026-2404

OPENSUSE-SU-2026:10691-1

RHSA-2026:13274

USN-8284-1

Affected Products

Linuxmint

Rocky Linux

Ubuntu

Gnutls

References · 94

• 🔥 https://gitlab.com/gnutls/gnutls/-/issues/1803 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-42015 · Security Note
• https://ubuntu.com/security/CVE-2026-42013 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-07116 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-3833 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-5419 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-33846 · Security Note
• https://errata.almalinux.org/8/ALSA-2026-20611.html · Vendor Advisory
• https://osv.dev/vulnerability/ALPINE-CVE-2026-3833 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-33846 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-42010 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-3833 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-3833 · Vendor Advisory
• https://osv.dev/vulnerability/USN-8284-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-42012 · Vendor Advisory