CVE-2026-42011 | Gnutls: gnutls: security bypass due to incorrect name constraint handling

A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were incorrectly ignored when previous Certificate Authorities (CAs) only had excluded name constraints. A remote attacker could exploit this to bypass critical name constraint checks during certificate validation. This bypass could lead to the acceptance of invalid certificates, potentially enabling spoofing or man-in-the-middle attacks against affected systems.

Published: 2026-05-07 Last update: 2026-06-02 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42011 is rated Low Risk (31.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42011

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-08 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42011

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.4 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 5.2 [email protected]

Weakness enumeration for CVE-2026-42011

GitHub Security Advisory for CVE-2026-42011

GHSA-568w-37qx-3qc6 · Severity: high — A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were...

OS Trackers for CVE-2026-42011

vendor priority summary link
debian not yet assigned CVE-2026-42011 not yet assigned priority: Debian including 1 source packages (gnutls28), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-42011
suse high CVE-2026-42011 severity important: SUSE including 10 source package names (gnutls-3.8.13-1.1, libgnutls-dane-devel-3.8.13-1.1, …), 10 product×package rows across 1 product lines (openSUSE Tumbleweed): Fixed 10. https://www.suse.com/security/cve/CVE-2026-42011/
ubuntu medium CVE-2026-42011 medium priority: Ubuntu including 1 source packages (gnutls28), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): released 5, needs-triage 3. https://ubuntu.com/security/CVE-2026-42011

Affected software / configurations for CVE-2026-42011

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-42011

cvelogic Threat Intelligence