CVE-2026-33810
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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 certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Go standard library | crypto/x509 | 1.26.0-0 < 1.26.2 | affected |
Weaknesses
- CWE-295: Improper Certificate Validation
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: yes
- Technical Impact: partial
CVE Program Container
Additional References
- http://www.openwall.com/lists/oss-security/2026/04/19/4
- http://www.openwall.com/lists/oss-security/2026/04/20/1
crypto/x509: golang: Go crypto/x509: Certificate validation bypass due to incorrect DNS constraint application
Additional References
- https://access.redhat.com/security/cve/CVE-2026-33810
- https://bugzilla.redhat.com/show_bug.cgi?id=2456335
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33810.json
- https://access.redhat.com/errata/RHSA-2026:14391
- https://access.redhat.com/errata/RHSA-2026:28047
- https://access.redhat.com/errata/RHSA-2026:34365
- https://access.redhat.com/errata/RHSA-2026:19719
- https://access.redhat.com/errata/RHSA-2026:19144
- https://access.redhat.com/errata/RHSA-2026:19135
- https://access.redhat.com/errata/RHSA-2026:19721
- https://access.redhat.com/errata/RHSA-2026:19720
- https://access.redhat.com/errata/RHSA-2026:19353
- https://access.redhat.com/errata/RHSA-2026:25089
- https://access.redhat.com/errata/RHSA-2026:26585
- https://access.redhat.com/errata/RHSA-2026:22862
- https://access.redhat.com/errata/RHSA-2026:22347
- https://access.redhat.com/errata/RHSA-2026:21769
- https://access.redhat.com/errata/RHSA-2026:23345
- https://access.redhat.com/errata/RHSA-2026:29854
- https://access.redhat.com/errata/RHSA-2026:26568
- https://access.redhat.com/errata/RHSA-2026:26571
- https://access.redhat.com/errata/RHSA-2026:13545
- https://access.redhat.com/errata/RHSA-2026:7291
- https://access.redhat.com/errata/RHSA-2026:22485
- https://access.redhat.com/errata/RHSA-2026:10155
- https://access.redhat.com/errata/RHSA-2026:10158
- https://access.redhat.com/errata/RHSA-2026:21772
- https://access.redhat.com/errata/RHSA-2026:9385
- https://access.redhat.com/errata/RHSA-2026:24478
- https://access.redhat.com/errata/RHSA-2026:22960
- https://access.redhat.com/errata/RHSA-2026:22958
- https://access.redhat.com/errata/RHSA-2026:22962
- https://access.redhat.com/errata/RHSA-2026:22959
- https://access.redhat.com/errata/RHSA-2026:22961
References
- https://go.dev/cl/763763
- https://go.dev/issue/78332
- https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU
- https://pkg.go.dev/vuln/GO-2026-4866
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