CVE-2026-33173

UNKNOWN 0.0

Rails Active Storage has possible content type bypass via metadata in direct uploads

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

3th

Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, `DirectUploadsController` accepts arbitrary metadata from the client and persists it on the blob. Because internal flags like `identified` and `analyzed` are stored in the same metadata hash, a direct-upload client can set these flags to skip MIME detection and analysis. This allows an attacker to upload arbitrary content while claiming a safe `content_type`, bypassing any validations that rely on Active Storage's automatic content type identification. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

CWE	CWE-925
Vendor	rails
Product	activestorage
Published	Mar 23, 2026
Last Updated	Mar 24, 2026

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Affected Versions

rails / activestorage

>= 8.1.0.beta1, < 8.1.2.1 >= 8.0.0.beta1, < 8.0.4.1 < 7.2.3.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/rails/rails/security/advisories/GHSA-qcfx-2mfw-w4cg github.com: https://github.com/rails/rails/commit/707c0f1f41f067fdf96d54e99d43b28dfaae7e53 github.com: https://github.com/rails/rails/commit/8fcb934caadc79c8cc4ce53287046d0f67005b3e github.com: https://github.com/rails/rails/commit/d9502f5214e2198245a4c1defe9cd02a7c8057d0 github.com: https://github.com/rails/rails/releases/tag/v7.2.3.1 github.com: https://github.com/rails/rails/releases/tag/v8.0.4.1 github.com: https://github.com/rails/rails/releases/tag/v8.1.2.1