eMudhra intermediate CA keys compromised: what to check on your servers

On 17 October 2026 a security researcher reported that the private keys of eight eMudhra intermediate CA certificates could be calculated from their public certificates, because they were generated with too little randomness. Six of them are TLS intermediates (DV, OV and EV) and two are code signing intermediates. Browsers and operating systems blocked them within hours to three days.

Who is affected

• Websites: only certificates that chain to emSign ECC Root CA - G3. Google reports that no TLS certificate under the six blocked intermediates was ever logged to Certificate Transparency, so no live website certificate is known to have been issued from them.
• Chrome: removes emSign ECC Root CA - G3 from its root store; the change is expected on all devices from 27 October 2026. Mozilla removed the same root from Firefox on 20 October.
• Code signing: the two EM OV CS CA intermediates are on the compromised list. Systems that verify code signed under eMudhra's code signing hierarchy should be reviewed.
• Indian DSC and eSign: MeitY and eMudhra say the Indian Digital Signature Certificate and eSign services run on separate infrastructure under the Controller of Certifying Authorities and are not affected.

What to do

• Check who issued your certificate: run our SSL checker on each public website. If the issuer names eMudhra or emSign, plan a replacement from another CA before 27 October.
• Update trust stores on servers and in containers (operating system , Node.js, Go, Python certifi, Java keystores, curl bundles), so non-browser software also rejects the blocked chains.
• Don't click through certificate warnings, including on internal tools.

Certificates sold on this store are issued by Sectigo, DigiCert, GeoTrust, Thawte and RapidSSL and are not affected.