[security] Go 1.27.3 and Go 1.26.10 are released

[anno...@golang.org]

Hello gophers,

We have just released Go versions 1.27.3 and 1.26.10, minor point releases.

These releases include 1 security fix following the security policy:

• crypto/x509: mitigation for security concerns with a specific Certificate Authority

  We're blocking trust in a small set of intermediate certificates due to specific security concerns around their operation.

  Verify will now filter out chains which contain these intermediates, preventing them from being returned to the caller.

  We highly recommend immediately upgrading to this release.

  This is CVE-2026-111943 and Go issue https://go.dev/issue/82345.

View the release notes for more information:
https://go.dev/doc/devel/release#go1.27.3

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 go1.27.3 and build as usual.

Thanks to everyone who contributed to the releases.

Cheers,
Carlos and David for the Go team

[Brian Candler]

I'm struggling to find a public discussion of this CVE, why it requires a code change in Go, and what the impact is. I've checked on Google and X, and all I can find is that the certs are from eMudhra.

The obvious questions are: shouldn't the CA simply revoke the affected intermediate certs? Is the problem that the CA can't or won't revoke them? Or that the revocation process itself is broken?

In any case, it's going to take a long time for all Go binaries to be re-built and re-released. If I'm running Go binaries that someone else has built and released prior to this toolchain update, what's my exposure?  Should all Go binaries which use TLS and/or X509 be considered compromised at this point?

[Jason E. Aten]

Still incomplete, but a little more info:

https://groups.google.com/a/mozilla.org/g/dev-security-policy/c/0R3XLJL6FuE/m/0XofdebrAAAJ?pli=1

[Brian Candler]

Thanks for that.  So it's not just Go affected. Now de-restricted: https://bugzilla.mozilla.org/show_bug.cgi?id=2083449

It seems Mozilla and Chrome are dealing with this by (in effect) pushing the CRL to their browsers, but also updating their trust stores to remove the root cert which signed these intermediate certs, for the benefit of third party apps which use their trust stores.  I guess we can expect vendors to push out corresponding updates to their root bundles soon.