The End of ClientAuth EKU…Oh Mercy…What to do?
If you’ve spent any time recently monitoring the cryptography and/or public key infrastructure (PKI) spaces…beyond that ever-present “post-quantum” thing, you may have read that starting in May of 2026, Google Chrome Root Program Policy will start requiring public certificate authorities (CAs) to stop issuing certificates with the Client Authentication Extended Key Usage (ClientAuth EKU) extension. While removing ClientAuth EKU from TLS server certificates correctly reduces the scope of these certificates, some internal client certificate authenticated TLS machine-to-machine and API workloads could fail when new/renewed certificates are received from a public CA. Read more here for details and options.
