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CVE

CVE-2026-33810

When verifying a certificate chain containing excluded DNS constraints, these constraints are not correctly applied to w

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.

HIGH · CVSS 8.2 EPSS 0.00013
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-295Improper Certificate Validation
▤

Affected Products & Versions

1
golang go>= 1.26.0 and < 1.26.2
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Go stdlib fixed in 1.26.2
▣

Scoring & Timeline

8.2
HIGH · CVSS v3.1 · security@golang.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD08 Apr 2026 · 02:16 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

30
suse-csafopenSUSE-SU-2026:20703-1
rhsaRHSA-2026:21769Important
rhsaRHSA-2026:22347Important
rhsaRHSA-2026:13545Important
rhsaRHSA-2026:21772Important
🔗

References & Sources

6
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://go.dev/cl/763763Patch
https://go.dev/issue/78332Issue Tracking
https://groups.google.com/g/golang-announce/c/0uYbvbPZRWUMailing ListRelease Notes
https://pkg.go.dev/vuln/GO-2026-4866Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/19/4
http://www.openwall.com/lists/oss-security/2026/04/20/1
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