MEDIUM6.5

GO-2025-4175

Improper application of excluded DNS name constraints when verifying wildcard names in crypto/x509

Quick fix

GO-2025-4175 — stdlib: upgrade to the fixed version with the command below.

go get stdlib@v1.24.11

Details

An excluded subdomain constraint in a certificate chain does not restrict the usage of wildcard SANs in the leaf certificate. For example a constraint that excludes the subdomain test.example.com does not prevent a leaf certificate from claiming the SAN *.example.com.

Are you affected?

Enter the version of the package you're using.

Affected packages

Go/stdlib

Introduced in: 0Fixed in: 1.24.11

Fixgo get stdlib@v1.24.11

References

https://go.dev/cl/723900[FIX]
https://go.dev/issue/76442[REPORT]
https://groups.google.com/g/golang-announce/c/8FJoBkPddm4[WEB]