Commuters who use the transit service have reported issues with its website and app, including that they are unable to buy tickets.
The outage affects other services including ChatGPT, social media platform X, Shopify, Dropbox, and Coinbase.
Cloudflare identified the issue impacting multiple customers and stated that its Dashboard and API were also failing.
The company has since made changes allowing Cloudflare Access and WARP to recover, re-enabling WARP access in London, and is continuing efforts to restore other affected services.