RCE in Rails
CVE-2026-66066
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.
Published · last modified .
EPSS exploit prediction
EPSS 0.329, 98.4th percentile (scored ); up from 0.279 30 days earlier. About EPSS.
EPSS over last 30 days · oldest: 0.279 · newest: 0.329 · change: +0.050
Affected products
- Rails — versions < 7.2.3.2, >= 8.0.0.beta1, < 8.0.5.1, >= 8.1.0.beta1, < 8.1.3.1
Weakness classification (CWE)
Public exploits and proof-of-concept code
Metasploit modules
11 public repositories with exploit or proof-of-concept code for this CVE:
- rails/rails-forensics-CVE-2026-66066 (30 stars, last pushed 2026-07-31)
- Zer0SumGam3/CVE-2026-66066-POC (23 stars, last pushed 2026-07-30): PoC for CVE-2026-66066 in Ruby on Rails
- 0xsha/KindaRails2Shell (5 stars, last pushed 2026-07-31): CVE-2026-66066 + File Read, RCE, Scanner, Lab
- HackSpeak/CVE-2026-66066 (4 stars, last pushed 2026-08-04): CVE-2026-66066 (KindaRails2Shell) PoC - Rails Active Storage/libvips arbitrary file read to RCE; for authorized security testing
- HackSpeak/kindarails2shell-poc (2 stars, last pushed 2026-08-03): CVE-2026-66066 (KindaRails2Shell) PoC - Rails Active Storage/libvips arbitrary file read to RCE; for authorized security testing
- shinthink/CVE-2026-66066 (1 star, last pushed 2026-08-04): CVE-2026-66066 — KindaRails2Shell: Rails Active Storage/libvips Arbitrary File Read → RCE. MATLAB/HDF5 dual-identity file → SECRET_KEY_BASE theft → forged variation. CVSS 9.5 | Rails < 8.1.3.1
- 0xBlackash/CVE-2026-66066 (1 star, last pushed 2026-07-31): CVE-2026-66066
- 0xredash/CVE-2026-66066 (1 star, last pushed 2026-07-31): CVE-2026-66066
- ashrafzaryouh/CVE-2026-66066 (1 star, last pushed 2026-07-31): CVE-2026-66066
- ivanesk315/CVE-2026-66066 (last pushed 2026-09-10)
1 more are listed on the interactive page.
References
- https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm
- 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/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-66066.yml
- https://thehackernews.com/2026/07/critical-rails-flaw-could-let.html
- www.openwall.com/lists/oss-security/2026/07/29/9
This CVE has public exploit evidence. See the latest CVEs with public exploits.