Security · Updated 21 Oct, 06:16 am IST
Eight eMudhra intermediate CA keys were compromised, browsers blocked them
Why it matters for readers: It matters because broken certificate keys let attackers impersonate websites, and major vendors have already blocked the affected certificates.
- Cloudflare detected the issue and deployed mitigations across its products, updating clients like WARP (1.1.1.1) and cloudflared to protect customers.2
- Researchers found the private keys were so weak that they could be recovered quickly; one published private key had an extremely small value.14
- The compromised eMudhra intermediates chain to roots trusted by Mozilla, Microsoft, Apple and Chrome, prompting those vendors to block the certificates.134
- The weakness was discovered by a researcher known as Wayne and responsibly disclosed to root program teams in mid‑October 2026.14
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Get startedHow this story developed
20 Oct, 07:28 pm · Hacker News (100+ points)
EMudhra Intermediate CA Compromise
21 Oct, 03:50 am · Cloudflare Blog
8 eMudhra certificates are compromised. Here's what you need to know
21 Oct, 05:20 am · Simon Willison
eMudhra Intermediate CA Compromise
21 Oct, 06:16 am · BleepingComputer
Mozilla, Google, Apple block compromised eMudhra CA certificates