# CVE-2026-33810

## Summary

- **CVE ID:** CVE-2026-33810
- **Severity:** HIGH
- **CVSS Score:** 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:L)
- **CWE:** N/A
- **Published:** Apr 8, 2026
- **Last Modified:** Sep 17, 2026

## 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.

## Affected Products

- Go standard library — crypto/x509 (1.26.0-0)

## References

- [CNA](https://go.dev/cl/763763)
- [CNA](https://go.dev/issue/78332)
- [CNA](https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU)
- [CNA](https://pkg.go.dev/vuln/GO-2026-4866)
- [CVE](http://www.openwall.com/lists/oss-security/2026/04/19/4)
- [CVE](http://www.openwall.com/lists/oss-security/2026/04/20/1)
- [redhat-SADP](https://access.redhat.com/security/cve/CVE-2026-33810)
- [redhat-SADP](https://bugzilla.redhat.com/show_bug.cgi?id=2456335)
- [redhat-SADP](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33810.json)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:14391)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:28047)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19719)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19144)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19135)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19721)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19720)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19353)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:25089)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:26585)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22862)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22347)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:21769)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:23345)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:29854)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:26568)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:26571)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:13545)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:7291)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22485)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:10155)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:10158)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:21772)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:9385)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:24478)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22960)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22958)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22962)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22959)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:22961)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:34365)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:36796)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:36651)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:39810)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:40118)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:40945)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:41928)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:42043)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:42047)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:42050)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:42051)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:42049)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:47952)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:51033)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:54757)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:51288)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:34192)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:34196)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:34197)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:57126)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19714)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:59546)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:49703)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:49702)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:56143)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:57649)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:49712)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:56223)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:61313)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:61253)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:61907)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:62578)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:62577)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:63332)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:65534)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:65359)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:65880)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:65126)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:66327)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:65895)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:67149)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:67134)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:67160)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:67159)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:67517)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:67518)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:68334)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:68504)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.34%
- **EPSS Percentile:** 27.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._