4 real? Tracking exploitation and patching of eMudhra’s weak keys

On October 19, 2026, we learned about eMudhra’s eight shockingly weak keys: where eMudhra was trusted to pick a 115-digit number for their virtual combination lock protecting the Internet, they picked the number 4. Not even four digits, just the number 4. The other seven keys were similarly weak: 56, 66, 115, 155, 156, 230 and 237.

The next day, we wrote a blog post on the immediate action we took to mitigate this leak, and what customers needed to do on their end to stay secure. Now, we are sharing a more in-depth follow up on the evidence we’ve seen of exploitation, and the progress seen on visitors patching their systems.

Let's start with the scale of the problem. A certificate authority (CA) with weak keys this serious is unprecedented, and the potential consequences are significant. While there have been plenty of compromised certification authorities in the past (such as DigiNotar, TÜRKTRUST, and TrustWave), access to their keys has always been contained to a degree; these incidents gave a limited set of attackers or organizations the ability to issue fraudulent certificates. The eMudhra incident is fundamentally different; the affected intermediate private keys could be recovered almost Continue reading

Protecting Project Galileo websites from HTTP attacks

Yesterday, we celebrated the fifth anniversary of Project Galileo. More than 550 websites are part of this program, and they have something in common: each and every one of them has been subject to attacks in the last month. In this blog post, we will look at the security events we observed between the 23 April 2019 and 23 May 2019.

Project Galileo sites are protected by the Cloudflare Firewall and Advanced DDoS Protection which contain a number of features that can be used to detect and mitigate different types of attack and suspicious traffic. The following table shows how each of these features contributed to the protection of sites on Project Galileo.