CVE-2026-33173: Rubyonrails Rails

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Rubyonrails Rails: before 7.2.3.1 (fixed in 7.2.3.1); from 8.0.0, before 8.0.4.1 (fixed in 8.0.4.1); from 8.1.0, before 8.1.2.1 (fixed in 8.1.2.1)

Published 2026-03-24. Last modified 2026-06-17.