Vulnerability Description
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.
Related Weaknesses (CWE)
References
- https://github.com/rails/rails/commit/1c01bb587206ee6eb0e1179c2cef96a6a47acb1e
- https://github.com/rails/rails/commit/349e7a5d5b4b715af1e416db824f3c078a7d59e5
- https://github.com/rails/rails/commit/d79b7f4aa17dec8ce4960fef05733c8c0c7ef49a
- https://github.com/rails/rails/releases/tag/v7.2.3.2
- https://github.com/rails/rails/releases/tag/v8.0.5.1
- https://github.com/rails/rails/releases/tag/v8.1.3.1
- https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2
- https://thehackernews.com/2026/07/critical-rails-flaw-could-let.html
- http://www.openwall.com/lists/oss-security/2026/07/29/9
- http://www.openwall.com/lists/oss-security/2026/08/01/6
- https://ethiack.com/info-hub/research/kindarails2shell-rails-rce-cve-2026-66066
- https://github.com/rails/rails-forensics-CVE-2026-66066
FAQ
What is CVE-2026-66066?
CVE-2026-66066 is a documented vulnerability. 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 untruste...
How severe is CVE-2026-66066?
CVSS scoring is not yet available for CVE-2026-66066. Check NVD for updates.
Is there a patch for CVE-2026-66066?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.