ShellCodeX Intelligence Brief
CRITICAL
Vulnerabilities
Rails Active Storage file disclosure risk via crafted image uploads (CVE-2026-66066)
Source headline: Critical Rails Flaw Could Let Unauthenticated Attackers Read Server Files via Image Uploads
Threat level
Critical
Signal strength
90/100
Source confidence
1 source
Published
2 hours ago
Intelligence Summary
Ruby on Rails has issued fixes for a critical Active Storage vulnerability. Affected apps can be tricked by crafted image uploads that allow unauthenticated attackers to read arbitrary files on the server. The flaw may expose sensitive Rails process data and secrets such as secret_key_base and the Rails master key. It can also leak database passwords and cloud storage credentials. Administrators should upgrade Rails/Active Storage to the patched versions and review exposure in any affected deployments.
Recommended Action
Prioritize immediate review, validate exposure, and patch or mitigate affected systems.
Topics
Original reporting
The Hacker News
Critical Rails Flaw Could Let Unauthenticated Attackers Read Server Files via Image Uploads
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