CVE-2026-66066Action Pack: Possible arbitrary file read and remote code execution in Active Storage variant processing
- 9.5CriticalCVSS base score
- 32.9%Exploitation in 30 daysEPSS · top 1.6% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 1Public exploitsMetasploit, Nuclei and Exploit-DB
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Metasploit module for it. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits2
Metasploit modules1 module
- Ruby on Rails Active Storage Vips Arbitrary File Read and Remote Code Execution (Metasploit module) (opens in a new tab)
exploit/multi/http/rails_activestorage_vips_rceRank normaldisclosed 29 Jul 2026
References tagged exploit1 reference
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By GitHub_M
- 7 days later
· 7 days later
Published
- 6 days later
· 6 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | Critical9.5 | 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 |
| NVDNVD · Awaiting Analysis | 4.0 | Critical9.5 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 32.9% · top 1.6% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.5.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemsactivestorageGHSA-xr9x-r78c-5hrm (opens in a new tab)
References
References13
- https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm (opens in a new tab)x_refsource_CONFIRM
- https://github.com/rails/rails/commit/1c01bb587206ee6eb0e1179c2cef96a6a47acb1e (opens in a new tab)x_refsource_MISC
- https://github.com/rails/rails/commit/349e7a5d5b4b715af1e416db824f3c078a7d59e5 (opens in a new tab)x_refsource_MISC
- https://github.com/rails/rails/commit/d79b7f4aa17dec8ce4960fef05733c8c0c7ef49a (opens in a new tab)x_refsource_MISC
- https://github.com/rails/rails/releases/tag/v7.2.3.2 (opens in a new tab)x_refsource_MISC
- https://github.com/rails/rails/releases/tag/v8.0.5.1 (opens in a new tab)x_refsource_MISC
- https://github.com/rails/rails/releases/tag/v8.1.3.1 (opens in a new tab)x_refsource_MISC
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-66066.yml (opens in a new tab)x_refsource_MISC
- https://thehackernews.com/2026/07/critical-rails-flaw-could-let.html (opens in a new tab)x_refsource_MISC
- http://www.openwall.com/lists/oss-security/2026/07/29/9 (opens in a new tab)
- https://ethiack.com/info-hub/research/kindarails2shell-rails-rce-cve-2026-66066 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/01/6 (opens in a new tab)
- https://github.com/rails/rails-forensics-CVE-2026-66066 (opens in a new tab)exploit
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-51270 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-xr9x-r78c-5hrm (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-66066)Record last updated .