At least Cloudflare is fast in sharing their postmortems.

https://blog.cloudflare.com/5-december-2025-outage/

A curious thing is this:

>>>
Customers that have their web assets served by our older FL1 proxy AND had the Cloudflare Managed Ruleset deployed were impacted. All requests for websites in this state returned an HTTP 500 error, with the small exception of some test endpoints such as /cdn-cgi/trace.
<<<

IIRC, in the previous incident on Nov 18, only the customers on the newer proxy version were impacted. So, one could say that Cloudflare had a single time-distributed total outage.

Another important thing:

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Before the end of next week we will publish a detailed breakdown of all the resiliency projects underway, including the ones listed above. While that work is underway, we are locking down all changes to our network in order to ensure we have better mitigation and rollback systems before we begin again.
<<<

Honestly, looking forward to seeing the write-up. I can only imagine how stressed their team is after taking down a big chunk of the Internet twice in less than 30 days.


#cloudflare #postmortem