Rails ActiveStorage libvips Unsafe Ops Leak Secrets 7.2.3.2, 8.0.5.1, 8.1.3.1
CVE-2026-66066 Published on July 30, 2026
Action Pack: Possible arbitrary file read and remote code execution in Active Storage variant processing
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.
Vulnerability Analysis
CVE-2026-66066 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
Insecure Default Initialization of Resource
The software initializes or sets a resource with a default that is intended to be changed by the administrator, but the default is not secure.
Products Associated with CVE-2026-66066
Want to know whenever a new CVE is published for Ruby on Rails? stack.watch will email you.
Affected Versions
rails:- Version < 7.2.3.2 is affected.
- Version >= 8.0.0.beta1, < 8.0.5.1 is affected.
- Version >= 8.1.0.beta1, < 8.1.3.1 is affected.