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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products
rails:rails
References 13
https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm
https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm
https://github.com/rails/rails/commit/1c01bb587206ee6eb0e1179c2cef96a6a47acb1e
https://github.com/rails/rails/commit/1c01bb587206ee6eb0e1179c2cef96a6a47acb1e
https://github.com/rails/rails/commit/349e7a5d5b4b715af1e416db824f3c078a7d59e5
https://github.com/rails/rails/commit/349e7a5d5b4b715af1e416db824f3c078a7d59e5
https://github.com/rails/rails/commit/d79b7f4aa17dec8ce4960fef05733c8c0c7ef49a
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/v7.2.3.2
https://github.com/rails/rails/releases/tag/v8.0.5.1
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/releases/tag/v8.1.3.1
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-…
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-66066.yml
https://thehackernews.com/2026/07/critical-rails-flaw-could-let.html
https://thehackernews.com/2026/07/critical-rails-flaw-could-let.html
http://www.openwall.com/lists/oss-security/2026/07/29/9
af854a3a-2127-422b-91ae-364da2661108
https://ethiack.com/info-hub/research/kindarails2shell-rails-rce-cve-2026-66066
af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/08/01/6
af854a3a-2127-422b-91ae-364da2661108
https://github.com/rails/rails-forensics-CVE-2026-66066
134c704f-9b21-4f2e-91b3-4a467353bcc0