{"id":"CVE-2026-33810","title":"When verifying a certificate chain containing excluded DNS constraints, these constraints are not correctly applied to wildcard DNS SANs which use a different case than the constraint","summary":"When verifying a certificate chain containing excluded DNS constraints, these constraints are not correctly applied to wildcard DNS SANs which use a different case than the constraint. This only affects validation of otherwise trusted ce…","severity":"high","cvss":8.2,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","cwe":["CWE-295","CWE-1289"],"vendor":"golang","product":"go","affected":["go >= 1.26.0, < 1.26.2"],"patched":["go 1.26.2"],"published":"2026-04-08","updated":"2026-09-18","sourceUpdated":"2026-09-18T13:17:56.113","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-33810","references":[{"url":"https://go.dev/cl/763763","label":"security@golang.org"},{"url":"https://go.dev/issue/78332","label":"security@golang.org"},{"url":"https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU","label":"security@golang.org"},{"url":"https://pkg.go.dev/vuln/GO-2026-4866","label":"security@golang.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/04/19/4","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2026/04/20/1","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2026:10155","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:10158","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:13545","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:14391","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19135","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19144","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19353","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19714","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19719","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19720","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19721","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:21769","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:21772","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22347","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22485","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22862","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22958","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22959","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22960","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22961","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:22962","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:23345","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:24478","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:25089","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:26568","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:26571","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:26585","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:28047","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:29854","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:34192","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:34196","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:34197","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:34365","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:36651","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:36796","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:39810","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:40118","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:40945","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:41928","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:42043","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/err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Overview\n\nWhen verifying a certificate chain containing excluded DNS constraints, these constraints are not correctly applied to wildcard DNS SANs which use a different case than the constraint. This only affects validation of otherwise trusted certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.\n\n## Affected\n\n- `go >= 1.26.0, < 1.26.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `go 1.26.2`\n\n## Package advisory (CVE-2026-33810)\n\nAffected packages:\n\n- `stdlib >= 1.26.0-0, < 1.26.2`\n\nPatched in:\n\n- `stdlib 1.26.2`\n\nSource: https://osv.dev/vulnerability/GO-2026-4866\n\n## Vendor advisories\n\n- **RHSA-2026:54757** · Red Hat · fixed in: Red Hat OpenStack Platform 16.2 · released 2026-08-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:54757)\n- **RHSA-2026:14391** · Red Hat · fixed in: Cryostat 4 on RHEL 9 · released 2026-05-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:14391)\n- **RHSA-2026:36796** · Red Hat · fixed in: RHEM 1.0 for RHEL 9 · released 2026-07-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:36796)\n- **RHSA-2026:28047** · Red Hat · fixed in: Red Hat OpenStack Platform 17.1 · released 2026-06-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:28047)\n- **RHSA-2026:39810** · Red Hat · fixed in: Red Hat OpenStack Services on OpenShift 18.0, 9Base-RHOSO-TOOLS-18 · released 2026-07-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:39810)\n- **RHSA-2026:34365** · Red Hat · fixed in: Red Hat Satellite 6.19 for RHEL 9 · released 2026-07-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:34365)\n- **RHSA-2026:49703** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-08-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:49703)\n- **RHSA-2026:49702** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-08-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:49702)\n- **RHSA-2026:56143** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-08-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:56143)\n- **RHSA-2026:59546** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59546)\n- **RHSA-2026:19719** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-05-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:19719)\n- **Red Hat VEX** · Important · affected: Assisted Installer for Red Hat OpenShift Container Platform 2, cert-manager Operator for Red Hat OpenShift, Confidential Compute Attestation, Deployment Validation Operator, Fence Agents Remediation Operator, File Integrity Operator, … · no fix planned: Confidential Compute Attestation, Gatekeeper 3, Multicluster Engine for Kubernetes, Red Hat 3scale API Management Platform 2, … · updated 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33810.json)\n- **RHSA-2026:67149** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67149)\n- **RHSA-2026:67517** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-09-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:67517)\n- **RHSA-2026:68334** · Red Hat · fixed in: RHEM 1.1 for RHEL 10, RHEM 1.1 for RHEL 9 · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68334)","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":45.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}