cloudflare How we mitigated a vulnerability in Cloudflare’s ACME validation logic (opens in new tab)
How we mitigated a vulnerability in Cloudflare’s ACME validation logic 2026-01-19 Hrushikesh Deshpande Andrew Mitchell Leland Garofalo This post was updated on January 20, 2026. On October 13, 2025, security researchers from FearsOff identified and reported a vulnerability in Cl…