October 04, 2023
On 4 October 2023, Cloudflare experienced DNS resolution problems. Some users may have received SERVFAIL DNS responses to valid queries. In this blog, we’re going to talk about what the failure was, why it occurred, and what we’re doing to make sure this doesn’t happen again...
August 02, 2023
A deep dive into the recent incidents relating to Workers KV, and how we’re going to fix them...
July 11, 2023
On July 9, 2023, users in the Asia Pacific region experienced connection errors due to origin DNS resolution failures to .com and .net TLD nameservers...
January 25, 2023
Several Cloudflare services became unavailable for 121 minutes on January 24th, 2023 due to an error releasing code that manages service tokens. The incident degraded a wide range of Cloudflare products...
October 26, 2022
Today, a change to our Tiered Cache system caused some requests to fail for users with status code 530...
June 21, 2022
Today, June 21, 2022, Cloudflare suffered an outage that affected traffic in 19 of our data centers...
April 05, 2022
This post tells the story of how a missing shell option called “pipefail” slowed Cloudflare down....
March 22, 2022
Today at 03:30 UTC we learnt of a compromise of Okta. We use Okta internally for employee identity as part of our authentication stack. We have investigated this compromise carefully and do not believe we have been compromised as a result...
January 26, 2022
On January 24, 2022, as a result of an internal product migration, 24 hostnames (including www.cloudflare.com) that were actively proxied through the Cloudflare global network were mistakenly redirected to the wrong origin...
November 27, 2020
At Cloudflare, we are always on the lookout for Single Points of Failure. In this post, we explore the role a failure mode known as a Byzantine fault played in a a real-world incident....
August 30, 2020
Today CenturyLink/Level(3), a major ISP and Internet bandwidth provider, experienced a significant outage that impacted some of Cloudflare’s customers as well as a significant number of other services and providers across the Internet. ...
July 18, 2020
Today a configuration error in our backbone network caused an outage for Internet properties and Cloudflare services that lasted 27 minutes. We saw traffic drop by about 50% across our network....
July 12, 2019
Almost nine years ago, Cloudflare was a tiny company and I was a customer not an employee. Cloudflare had launched a month earlier and one day alerting told me that my little site, jgc.org, didn’t seem to have working DNS any more. ...
July 02, 2019
Starting at 1342 UTC today we experienced a global outage across our network that resulted in visitors to Cloudflare-proxied domains being shown 502 errors (“Bad Gateway”). The cause of this outage was deployment of a single misconfigured rule within the Cloudflare Web Applicatio...
June 26, 2019
On Monday we wrote about a painful Internet wide route leak. We wrote that this should never have happened because Verizon should never have forwarded those routes to the rest of the Internet. Today we will dive into the archived routing data and analyze it....
June 01, 2018
Cloudflare is protected from attacks by the Gatebot DDoS mitigation pipeline. Gatebot performs hundreds of mitigations a day, shielding our infrastructure and our customers from L3 and L7 attacks. ...
March 01, 2017
Last Thursday we released details on a bug in Cloudflare's parser impacting our customers. It was an extremely serious bug that caused data flowing through Cloudflare's network to be leaked onto the Internet....
February 23, 2017
Last Friday, Tavis Ormandy from Google’s Project Zero contacted Cloudflare to report a security problem with our edge servers. He was seeing corrupted web pages being returned by some HTTP requests run through Cloudflare....
January 01, 2017
At midnight UTC on New Year’s Day, deep inside Cloudflare’s custom RRDNS software, a number went negative when it should always have been, at worst, zero. A little later this negative value caused RRDNS to panic. ...
