TORONTO, Nov. 3, 2026 — A forged certificate dated less than an hour after Mozilla's bug report on eMudhra's weak keys went public is the clearest sign yet that revoking a compromised certificate authority is only the start of the cleanup, Securetron said today. In a follow-up published October 30, Cloudflare reported that one forged certificate it observed was dated October 20 at 18:19 UTC, less than an hour after the weakness became public, and that patching progress among the clients it could measure had largely stalled after the first weekend.

Cloudflare learned on October 19 that eight eMudhra intermediate keys were so weak they could be recovered almost instantly by anyone from the public certificates themselves. The keys were the numbers 4, 56, 66, 115, 155, 156, 230 and 237. eMudhra has said it is exiting the public certificate authority business and has claimed a mistake in a key-generation script, which it had not shared at the time Cloudflare wrote. Cloudflare patched its high-priority systems within hours and completed an AI-assisted analysis of its other systems trusting the weak keys within four hours.

To track attempted use of the keys, Cloudflare added logging to Pingora, its origin-facing proxy service, with the rollout finished on October 21. In the week that followed it recorded about 22,000 attempted handshakes presenting certificates signed by the weak eMudhra keys. Two-thirds were fetches of test sites. Almost all of the remaining third went to origins that appeared to have set up a certificate for themselves using the weak intermediate, and every handshake configured to verify the certificate was refused, because Cloudflare had already patched.

About 160 handshakes stood out. Their certificates named other organizations' domains in their Subject Alternative Names, unrelated to the domain requested, some related to consumer Internet of Things devices, and some were valid for over two years. Cloudflare's reading is that these looked like the servers' own default certificates rather than an interception attempt, that they would have failed hostname verification anyway, and that in several cases the same certificate was presented from many Cloudflare locations, meaning it came from the server itself. Cloudflare states there is no evidence so far of the weak keys being used to intercept its connections, while noting that this does not exclude carefully targeted interception, for which it has seen no indirect compromise signals.

The longer tail is on the client side. Cloudflare measured visitor patching indirectly, sending two probe connections from a fraction of its challenge pages, one presenting an eMudhra-signed certificate and one a control certificate, recording 50 million probes over the week. Up-to-date modern browsers are mostly patched, Cloudflare found, but bots and old browsers are not, and embedded browsers such as Android WebView lag behind, with 30 to 40 percent still accepting the compromised chain. Across large networks, more than half of probes still accepted the compromised chain. Patching evidence appeared over the first weekend, Cloudflare said, and then showed little movement afterwards, except for Chrome 150 to 154 on Linux, whose acceptance continues to decline.

Cloudflare cautions that challenge-page traffic is highly skewed, that many unconfirmed bots are included, and that only clients executing JavaScript send probes, so the bot-heavy and changing traffic mix makes the evidence suggestive rather than conclusive for some cohorts. The probe percentages should not be read as a measurement of all Internet clients.

"Browser removal and revocation do not reach every place a certificate chain is trusted," said Sarah Reid, Securetron. "The long tail is embedded browsers, old clients, bots, containers and runtimes that nobody inventoried. You cannot clean up a trust store you have not found, and a patch to one store does not patch the others."

Securetron's PKI Trust Manager continuously discovers certificates, expiring assets and vulnerabilities across an enterprise, with automated issuance, renewal and monitoring for the entire certificate lifecycle. It includes a built-in RFC 8555 ACME server with External Account Binding, plus SCEP and EST enrolment, so tools such as certbot, acme.sh and win-acme and network devices enrol automatically. A single pane of glass covers ADCS, MSCA, Let's Encrypt, DigiCert and ACME, with full audit trails for every action, and expiry alerting with configurable lead times and routing. Boltron-AI, the AI-based automation module for PKI Trust Manager, discovers applications and services, profiles their configurations and generates onboarding runbooks. The Community Edition manages up to 500 certificates free of charge, on premises or as a service through PKI Trust Cloud.

Securetron does not claim PKI Trust Manager patches browsers, embedded clients or runtimes, or that it would have blocked this incident. The product addresses the inventory and lifecycle side: finding every certificate and trust store, automating renewal and replacement, and keeping an audit trail of what changed.

About Securetron: Securetron automates certificate lifecycle management with PKI Trust Manager and PKI Trust Cloud, including discovery, application inventory, configuration intelligence and AI-driven onboarding with Boltron-AI. Learn more at https://securetron.net.

Press contact: Sarah Reid, Securetron, 1 Yonge St, Toronto, ON M5E 1E6, Canada, +1 (438) 927-8036, [email protected].