CVE-2026-27137

Incorrect enforcement of email constraints in crypto/x509

CVSS 7.5 HIGHEPSS 0.4%

When verifying a certificate chain which contains a certificate containing multiple email address constraints which share common local portions but different domain portions, these constraints will not be properly applied, and only the last constraint will be considered.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Go standard library · crypto/x509

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References

https://go.dev/cl/752182 https://go.dev/issue/77952 https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk https://pkg.go.dev/vuln/GO-2026-4599