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 certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.

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Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

References
Link Providers
http://www.openwall.com/lists/oss-security/2026/04/19/4 cve-icon
http://www.openwall.com/lists/oss-security/2026/04/20/1 cve-icon
https://access.redhat.com/errata/RHSA-2026:10155 cve-icon
https://access.redhat.com/errata/RHSA-2026:10158 cve-icon
https://access.redhat.com/errata/RHSA-2026:13545 cve-icon
https://access.redhat.com/errata/RHSA-2026:14391 cve-icon
https://access.redhat.com/errata/RHSA-2026:19135 cve-icon
https://access.redhat.com/errata/RHSA-2026:19144 cve-icon
https://access.redhat.com/errata/RHSA-2026:19353 cve-icon
https://access.redhat.com/errata/RHSA-2026:19719 cve-icon
https://access.redhat.com/errata/RHSA-2026:19720 cve-icon
https://access.redhat.com/errata/RHSA-2026:19721 cve-icon
https://access.redhat.com/errata/RHSA-2026:21769 cve-icon
https://access.redhat.com/errata/RHSA-2026:21772 cve-icon
https://access.redhat.com/errata/RHSA-2026:22347 cve-icon
https://access.redhat.com/errata/RHSA-2026:22485 cve-icon
https://access.redhat.com/errata/RHSA-2026:22862 cve-icon
https://access.redhat.com/errata/RHSA-2026:22958 cve-icon
https://access.redhat.com/errata/RHSA-2026:22959 cve-icon
https://access.redhat.com/errata/RHSA-2026:22960 cve-icon
https://access.redhat.com/errata/RHSA-2026:22961 cve-icon
https://access.redhat.com/errata/RHSA-2026:22962 cve-icon
https://access.redhat.com/errata/RHSA-2026:23345 cve-icon
https://access.redhat.com/errata/RHSA-2026:24478 cve-icon
https://access.redhat.com/errata/RHSA-2026:25089 cve-icon
https://access.redhat.com/errata/RHSA-2026:26568 cve-icon
https://access.redhat.com/errata/RHSA-2026:26571 cve-icon
https://access.redhat.com/errata/RHSA-2026:26585 cve-icon
https://access.redhat.com/errata/RHSA-2026:28047 cve-icon
https://access.redhat.com/errata/RHSA-2026:29854 cve-icon
https://access.redhat.com/errata/RHSA-2026:34365 cve-icon
https://access.redhat.com/errata/RHSA-2026:36651 cve-icon
https://access.redhat.com/errata/RHSA-2026:36796 cve-icon
https://access.redhat.com/errata/RHSA-2026:39810 cve-icon
https://access.redhat.com/errata/RHSA-2026:40118 cve-icon
https://access.redhat.com/errata/RHSA-2026:40945 cve-icon
https://access.redhat.com/errata/RHSA-2026:41928 cve-icon
https://access.redhat.com/errata/RHSA-2026:42043 cve-icon
https://access.redhat.com/errata/RHSA-2026:42047 cve-icon
https://access.redhat.com/errata/RHSA-2026:42049 cve-icon
https://access.redhat.com/errata/RHSA-2026:42050 cve-icon
https://access.redhat.com/errata/RHSA-2026:42051 cve-icon
https://access.redhat.com/errata/RHSA-2026:47952 cve-icon
https://access.redhat.com/errata/RHSA-2026:51033 cve-icon
https://access.redhat.com/errata/RHSA-2026:7291 cve-icon
https://access.redhat.com/errata/RHSA-2026:9385 cve-icon
https://access.redhat.com/security/cve/CVE-2026-33810 cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2456335 cve-icon
https://go.dev/cl/763763 cve-icon cve-icon cve-icon
https://go.dev/issue/78332 cve-icon cve-icon cve-icon
https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-33810 cve-icon
https://pkg.go.dev/vuln/GO-2026-4866 cve-icon cve-icon cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33810.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-33810 cve-icon
History

Mon, 20 Apr 2026 18:30:00 +0000

Type Values Removed Values Added
References

Sun, 19 Apr 2026 23:30:00 +0000

Type Values Removed Values Added
References

Fri, 17 Apr 2026 20:45:00 +0000

Type Values Removed Values Added
First Time appeared Golang
Golang go
Weaknesses CWE-295
CPEs cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
Vendors & Products Golang
Golang go

Tue, 14 Apr 2026 16:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-295

Tue, 14 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1289
References
Metrics threat_severity

None

threat_severity

Important


Mon, 13 Apr 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 09 Apr 2026 08:30:00 +0000

Type Values Removed Values Added
First Time appeared Go Standard Library
Go Standard Library crypto/x509
Vendors & Products Go Standard Library
Go Standard Library crypto/x509

Wed, 08 Apr 2026 20:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-295

Wed, 08 Apr 2026 01:45:00 +0000

Type Values Removed Values Added
Description 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 certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.
Title Case-sensitive excludedSubtrees name constraints cause Auth Bypass in crypto/x509
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Go

Published:

Updated: 2026-08-13T12:04:21.312Z

Reserved: 2026-03-23T20:35:32.814Z

Link: CVE-2026-33810

cve-icon Vulnrichment

Updated: 2026-04-20T17:23:21.823Z

cve-icon NVD

Status : Modified

Published: 2026-04-08T02:16:03.950

Modified: 2026-08-13T13:18:22.660

Link: CVE-2026-33810

cve-icon Redhat

Severity : Important

Publid Date: 2026-04-08T01:06:56Z

Links: CVE-2026-33810 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-18T17:30:05Z

Weaknesses