CVE-2026-66066
CriticalCVSS 9.5Exploitation Probability (EPSS)
Elevated risk75th percentile - higher than 75% of all known CVEs
Summary
Action Pack (Active Storage) prior to versions 7.2.3.2, 8.0.5.1 and 8.1.3.1 does not disable unsafe libvips operations for untrusted content, allowing a crafted upload to read arbitrary files accessible to the Rails process.
Risk Assessment
An unauthenticated attacker can read sensitive data such as secret_key_base or external-service tokens, potentially enabling remote code execution or lateral movement.
Recommendation
Update Action Pack to versions 7.2.3.2, 8.0.5.1 or 8.1.3.1 which contain the fix.
Original NVD description (English source)
Action Pack is a framework for handling and responding to web requests. In versions prior to 7.2.3.2, 8.0.5.1 and 8.1.3.1, Active Storage does not disable libvips operations marked unsafe for untrusted content, allowing a crafted upload to invoke such an operation. Consuming applications are affected when configured to use libvips and accept image uploads from untrusted users. An unauthenticated attacker may exploit this behavior to read arbitrary files accessible to the Rails process, including environment variables and application secrets. Exposure of credentials such as secret_key_base or external-service tokens may enable remote code execution or lateral movement. This issue has been fixed in versions 7.2.3.2, 8.0.5.1 and 8.1.3.1.