eMudhra Statement on Recent Certificate Security Incident

On 20 October 2026, Mozilla published a post on its Security Blog regarding eMudhra intermediate certificates. According to Mozilla:

eMudhra is actively investigating a security incident involving a specific set of intermediate CA certificates created as part of a Key Generation Ceremony (KGC) conducted in April 2025 within its public trust infrastructure.

The incident is limited to these specific intermediate CA certificates and does not affect eMudhra's root CA private keys or other intermediate CAs.

Importantly, none of the affected intermediate CAs were deployed in production, with the exception of one. Furthermore, none of these intermediate CAs, including the one deployed in production, have issued any end-entity certificates. This has been confirmed through our internal analysis and corroborated by publicly available Certificate Transparency records on crt.sh.

Upon becoming aware of the incident, eMudhra initiated its incident response procedures, took measures to contain the affected certificates, and began working closely with browser and root-store operators to safeguard users and maintain the integrity of the broader WebPKI ecosystem.

We are conducting a thorough investigation into the circumstances surrounding the incident and reviewing our security controls and operational procedures to identify and implement any necessary improvements.

The security and integrity of our trust services remain our highest priority. We are committed to transparency, adherence to industry standards, and continued collaboration with the global WebPKI community.

To avoid any misunderstanding, the removal of our Root CA’s C1 and C3 with Mozilla was a voluntary and planned activity and does not pertain to this security incident.

We will provide further updates as our investigation progresses and additional findings are confirmed.

What happened, who is affected, and what we are doing about it

On October 18, 2026, an independent security researcher reported that the keys of eight (out of several) eMudhra Global TLS intermediate Certificate Authorities (CAs) were cryptographically weak. We revoked all eight intermediates the following day. No certificates had been issued from any of them, our infrastructure was not compromised, and no data was breached.

We take this incident seriously. We believe an organization's character is shown in how it responds when something goes wrong, so this post sets out plainly what happened, who is affected, and what we are doing about it.

Eight intermediate (issuing) CAs in our Global TLS business were revoked because their published keys were weak. These intermediates sit under eMudhra's ECC root. As a consequence of the incident, the browser root programs have also distrusted that one ECC root.

To be clear about what was and was not affected:

The keys were generated on FIPS 140-2 Level 3 certified Hardware Security Modules (HSMs). Suggestions that HSMs were not used are incorrect. The problem was a flaw in one step of the ceremony procedure, not the absence of HSMs.

During the ceremony, a key wrap/unwrap step produced a second, weak set of keys alongside the original strong keys. The weak keys were the ones published to the browser root stores. The issue went undetected for about 18 months, through two independent audit cycles. The researcher was able to reverse-engineer the weak keys, reportedly with the help of AI-assisted tooling.

We have not yet confirmed the exact root cause. We will publish it in full once our investigation is complete. We are not aware of any evidence that the weak keys were recovered or exploited by anyone before the issue was disclosed.

The impact is limited to TLS certificates chaining to the distrusted ECC root, and it is contained to a single customer ecosystem in the United States.

These products and services run on separate infrastructure and continue to operate normally. Customers using them do not need to take any action.

Our first priority is making sure the affected customer's services keep running without disruption.

CA redundancy for all Enterprise TLS customers. We are offering every Enterprise TLS customer certificates from an additional publicly trusted CA. If one hierarchy ever has a problem, customers can switch without interrupting their business. Keeping our customers running is one of our top priorities.

A full review of our key generation process. We are reviewing every step of our Key Generation Ceremonies, starting with the wrap/unwrap step that caused this incident. We intend to deeply study how we can enhance the governance around our processes, and adopt AI based tooling in addition to other conventional means available to mitigate such occurences.

We acknowledge this incident and take full responsibility for it. Trust is the foundation of everything we do, and we intend to earn it back through action.

We thank the independent researcher who reported this issue responsibly, and our customers and partners for their trust.