criticalVulnerability

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.

Properties

severity
critical
summary
Active Storage has possible arbitrary file read and remote code execution in Active Storage variant processing
epss_score
0.27861
ghsa_published
2026-07-30T18:23:33Z
source_url
https://github.com/advisories/GHSA-xr9x-r78c-5hrm
ghsa_updated
2026-07-30T18:23:34Z
ghsa_id
GHSA-xr9x-r78c-5hrm
cve_id
CVE-2026-66066
signal_observed_at
2026-09-11T17:54:55+00:00
is_ghsa_only
false
published_at
2026-07-30T19:18:35.843
last_modified
2026-09-10T20:36:14.340
epss_percentile
0.9798

Related Entities (6)

DESCRIBED_BY (1)

[Source]NVD

ENRICHED_BY (1)

[Source]FIRST EPSS

VULNERABLE_TO (1)

[Software]rubygems/activestorage

AFFECTS (1)

[Software]rubygems/activestorage

HAS_WEAKNESS (1)

[Weakness]Initialization of a Resource with an Insecure Default

REPORTED_BY (1)

[Source]GitHub Advisory Database

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CVE-2026-66066 — Ninja Signal Threat Intelligence | Ninja Signal