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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-66066 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 9.5 CRITICAL
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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
http://www.openwall.com/lists/oss-security/2026/07/29/9 CVE
https://github.com/rails/rails/commit/1c01bb587206ee6eb0e1179c2cef96a6a47acb1e GitHub, Inc.
https://github.com/rails/rails/commit/349e7a5d5b4b715af1e416db824f3c078a7d59e5 GitHub, Inc.
https://github.com/rails/rails/commit/d79b7f4aa17dec8ce4960fef05733c8c0c7ef49a GitHub, Inc.
https://github.com/rails/rails/releases/tag/v7.2.3.2 GitHub, Inc.
https://github.com/rails/rails/releases/tag/v8.0.5.1 GitHub, Inc.
https://github.com/rails/rails/releases/tag/v8.1.3.1 GitHub, Inc.
https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm GitHub, Inc.
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-66066.yml GitHub, Inc.
https://thehackernews.com/2026/07/critical-rails-flaw-could-let.html GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-1188 Insecure Default Initialization of Resource GitHub, Inc.  

Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-66066
NVD Published Date:
07/30/2026
NVD Last Modified:
07/30/2026
Source:
GitHub, Inc.