Hello gophers,
We have just released Go versions 1.25.5 and 1.24.11, minor point releases.
These releases include 2 security fixes following the security policy:
crypto/x509: excessive resource consumption in printing error string for host certificate validation
Within HostnameError.Error(), when constructing an error string, there is no limit to the number of hosts that will be printed out.
Furthermore, the error string is constructed by repeated string concatenation, leading to quadratic runtime.
Therefore, a certificate provided by a malicious actor can result in excessive resource consumption.
HostnameError.Error() now limits the number of hosts and utilizes strings.Builder when constructing an error string.
Thanks to Philippe Antoine (Catena cyber) for reporting this issue.
This is CVE-2025-61729 and Go issue https://go.dev/issue/76445.
crypto/x509: excluded subdomain constraint does not restrict wildcard SANs
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.
This is CVE-2025-61727 and Go issue https://go.dev/issue/76442.
View the release notes for more information:
https://go.dev/doc/devel/release#go1.25.5
You can download binary and source distributions from the Go website:
https://go.dev/dl/
To compile from source using a Git clone, update to the release with
git checkout go1.25.5 and build as usual.
Thanks to everyone who contributed to the releases.
Cheers,
Dmitri and Cherry for the Go team