--- id: CVE-2026-3833 title: A flaw was found in gnutls summary: >- 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 `perm… severity: medium cvss: 6.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N' cwe: - CWE-178 vendor: gnu product: gnutls affected: - gnutls - hardened_images - openshift_container_platform = 4.0 - enterprise_linux = 6.0 - enterprise_linux = 7.0 - enterprise_linux = 8.0 - enterprise_linux = 9.0 - enterprise_linux = 10.0 patched: - enterprise_linux_server_v_7_els - openshift_container_platform 4.12 - openshift_container_platform 4.16 - openshift_container_platform 4.17 - openshift_container_platform 4.19 - enterprise_linux_appstream_eus_v_10_0 - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_8 - enterprise_linux_appstream_aus_v_8_4 - enterprise_linux_appstream_eus_extension_v_8_4 - enterprise_linux_appstream_aus_v_8_6 - enterprise_linux_appstream_eus_extension_v_8_6 - enterprise_linux_appstream_e4s_v_8_8 - enterprise_linux_appstream_tus_v_8_8 - enterprise_linux_appstream_e4s_v_9_2 - enterprise_linux_appstream_e4s_v_9_4 - enterprise_linux_appstream_eus_v_9_6 - enterprise_linux_appstream_v_9 - enterprise_linux_baseos_eus_v_10_0 - enterprise_linux_baseos_v_10 - enterprise_linux_baseos_v_8 - enterprise_linux_baseos_aus_v_8_4 - enterprise_linux_baseos_eus_extension_v_8_4 - enterprise_linux_baseos_aus_v_8_6 - enterprise_linux_baseos_eus_extension_v_8_6 - enterprise_linux_baseos_e4s_v_8_8 - enterprise_linux_baseos_tus_v_8_8 - enterprise_linux_baseos_e4s_v_9_2 - enterprise_linux_baseos_e4s_v_9_4 - enterprise_linux_baseos_eus_v_9_6 - enterprise_linux_baseos_v_9 - discovery 2 - hardened_images - update_infrastructure 5 published: '2026-04-30' updated: '2026-09-17' sourceUpdated: '2026-09-17T19:16:45.917' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-3833' references: - url: 'https://access.redhat.com/errata/RHSA-2026:13274' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:20611' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:20612' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:20613' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:26319' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:26409' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:29197' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:30004' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:30849' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:30850' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:32962' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:33125' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:41921' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:43575' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:57402' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:58981' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:59831' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:60019' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:62409' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:62549' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:65839' label: secalert@redhat.com - url: 'https://access.redhat.com/errata/RHSA-2026:65851' label: secalert@redhat.com - url: 'https://access.redhat.com/security/cve/CVE-2026-3833' label: secalert@redhat.com - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2445763' label: secalert@redhat.com - url: 'https://gitlab.com/gnutls/gnutls/-/issues/1803' label: secalert@redhat.com - url: 'https://gitlab.com/gnutls/gnutls/-/issues/1803' label: 134c704f-9b21-4f2e-91b3-4a467353bcc0 - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3833.json - url: 'https://www.cve.org/CVERecord?id=CVE-2026-3833' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-3833' tags: - nvd - cve.org - exploit-available - csaf - vex - red-hat exploitAvailable: true ssvc: exploitation: poc automatable: 'yes' technicalImpact: partial timestamp: '2026-04-30T18:37:27.251775Z' epss: 0.00565 epssPercentile: 0.45722 ingestedAt: '2026-06-26T16:43:13.634Z' --- ## Overview 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. ## Affected - `gnutls` - `hardened_images` - `openshift_container_platform = 4.0` - `enterprise_linux = 6.0` - `enterprise_linux = 7.0` - `enterprise_linux = 8.0` - `enterprise_linux = 9.0` - `enterprise_linux = 10.0` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **RHSA-2026:43575** · Red Hat · fixed in: Red Hat Enterprise Linux Server (v. 7 ELS) · released 2026-07-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:43575) - **RHSA-2026:59831** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.12 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:59831) - **RHSA-2026:62549** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.16 · released 2026-09-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:62549) - **RHSA-2026:60019** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.17 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:60019) - **RHSA-2026:57402** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.19 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:57402) - **RHSA-2026:26409** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0) · released 2026-06-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:26409) - **RHSA-2026:20613** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-05-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:20613) - **RHSA-2026:20611** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-05-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:20611) - **RHSA-2026:33125** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4), Red Hat Enterprise Linux BaseOS AUS (v.8.4), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) · released 2026-06-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:33125) - **RHSA-2026:30849** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6), Red Hat Enterprise Linux BaseOS AUS (v.8.6), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) · released 2026-06-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:30849) - **RHSA-2026:30850** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8), Red Hat Enterprise Linux BaseOS E4S (v.8.8), Red Hat Enterprise Linux BaseOS TUS (v.8.8) · released 2026-06-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:30850) - **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat OpenShift Container Platform 4 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3833.json) - **RHSA-2026:62409** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.14 · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:62409) - **RHSA-2026:65851** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.18 · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:65851) - **RHSA-2026:65839** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.13 · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:65839)