Detections
Analytics
CVE-2026-66066
critical
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.
References
https://thehackernews.com/2026/07/critical-rails-flaw-could-let.html
https://ethiack.com/info-hub/research/kindarails2shell-rails-rce-cve-2026-66066
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-66066.yml
https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm
https://github.com/rails/rails/releases/tag/v8.1.3.1
https://github.com/rails/rails/releases/tag/v8.0.5.1
https://github.com/rails/rails/releases/tag/v7.2.3.2
https://github.com/rails/rails/commit/d79b7f4aa17dec8ce4960fef05733c8c0c7ef49a
https://github.com/rails/rails/commit/349e7a5d5b4b715af1e416db824f3c078a7d59e5
https://github.com/rails/rails/commit/1c01bb587206ee6eb0e1179c2cef96a6a47acb1e
Details
Published: 2026-07-30
Updated: 2026-07-31
Named Vulnerability: KindaRails2Shell
Risk Information
CVSS v2
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
CVSS v3
Base Score: 9.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
CVSS v4
Base Score: 9.5
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Severity: Critical
EPSS
EPSS: 0.01701
Vulnerability Watch
Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.
Vulnerability Being Monitored