eMudhra (emSign): security status

Summary

Official statement (published Oct 20, updated Oct 28, investigation ongoing): the private keys of eight intermediate CAs created on 2025-04-30 were flawed (reported by an outside researcher on Oct 17); misused, they could issue certificates for any domain. eMudhra revoked all eight on Oct 18. Seven were never used in production and the one that was issued no site certificates, it says. Browsers blocked them, and Mozilla removed their root, emSign ECC Root CA - G3, on Oct 20. Impact is limited to certificates chaining to that root (one customer group in the US); G1-root certificates remain valid and eSignature and similar customers need do nothing. Sectigo-issued certificates are offered as an alternative. In a public apology on Oct 26 it said a script error issued the CAs with weak keys, that they were revoked within 14 hours of confirming the issue, and that its infrastructure and customer data were not compromised; it is moving affected G3 customers and its other TLS customers to alternate certificates at no cost. It will publish a root-cause analysis through CCADB and has commissioned an independent review. Its Oct 28 update (Update 6) says the roughly 30,800 certificates issued under the affected G3 hierarchies belong to one client ecosystem in the US, which is already using an alternate issuance pathway through eMudhra's G1 RSA root. As part of a voluntary wind-down of publicly trusted TLS services, eMudhra will stop issuing TLS certificates from G1 once that client's transition is complete. A vast majority of its other TLS customers have already been moved to alternate providers at no cost, and it intends to finish the rest in the coming days. Its digital signature (DSC, eSign) business and emSigner, CertiNext, SecurePass and PrivaTrust are unaffected, it says.