Rails Active Storage has possible content type bypass via metadata in direct uploads
Published: March 23, 2026
SECURITY IDENTIFIERS
- CVE: CVE-2026-33173 (NVD)
- GHSA: GHSA-qcfx-2mfw-w4cg
- Vendor Advisory: https://github.com/rails/rails/security/advisories/GHSA-qcfx-2mfw-w4cg
GEM
FRAMEWORK
PATCHED VERSIONS
~> 7.2.3, >= 7.2.3.1
~> 8.0.4, >= 8.0.4.1
>= 8.1.2.1
DESCRIPTION
Impact
Active Storage's 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 malicious direct-upload client could set these flags.
Releases
The fixed releases are available at the normal locations.
RELATED
- https://github.com/rails/rails/security/advisories/GHSA-qcfx-2mfw-w4cg
- https://github.com/rails/rails/commit/707c0f1f41f067fdf96d54e99d43b28dfaae7e53
- https://github.com/rails/rails/commit/8fcb934caadc79c8cc4ce53287046d0f67005b3e
- https://github.com/rails/rails/commit/d9502f5214e2198245a4c1defe9cd02a7c8057d0
- https://github.com/rails/rails/releases/tag/v7.2.3.1
- https://github.com/rails/rails/releases/tag/v8.0.4.1
- https://github.com/rails/rails/releases/tag/v8.1.2.1
- https://github.com/advisories/GHSA-qcfx-2mfw-w4cg