Critical Rails Flaw Could Let Unauthenticated Attackers Read Server Files via Image Uploads
Critical Rails Flaw Could Let Unauthenticated Attackers Read Server Files via Image Uploads
29 July 2026
Ruby on Rails has released fixes for a critical Active Storage vulnerability that could let unauthenticated attackers read arbitrary files from application servers through crafted image uploads.
Tracked as CVE-2026-66066 (CVSS score: 9.5), the flaw can expose the Rails process environment and secrets such as secret_key_base, the Rails master key, database passwords, cloud storage credentials,