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CVE

CVE-2026-66066

Action Pack: Possible arbitrary file read and remote code execution in Active Storage variant processing
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CVE

CVE-2026-66066

Action Pack: Possible arbitrary file read and remote code execution in Active Storage variant processing

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 secretkeybase 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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.5
-
4.0
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
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

http://www.openwall.com/lists/oss-security/2026/07/29/9, http://www.openwall.com/lists/oss-security/2026/08/01/6, https://ethiack.com/info-hub/research/kindarails2shell-rails-rce-cve-2026-66066, 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://thehackernews.com/2026/07/critical-rails-flaw-could-let.html, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66066.json, https://github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm, https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-66066.yml, https://nvd.nist.gov/vuln/detail/CVE-2026-66066, 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-forensics-CVE-2026-66066

Severity

0

CVSS Score
0
10

Basic Information

Base CVSS
0
EPSS Probability
0.01767%
EPSS Percentile
0.76177%
Introduced Version
80827ca7ff33ca3026f2c74fe8249ccc6f513318,0
Fix Available
d79b7f4aa17dec8ce4960fef05733c8c0c7ef49a,18.10.8-r6,18.11.8-r0,18.8.11-r4,18.9.8-r7,19.0.5-r0,18.10.8-r7,19.0.4-r9,19.2.1-r0,3.8.0-r3,8.0.5.1-r0

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