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CVE-2026-33173GHSA-QCFX-2MFW-W4CG

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

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 8.1.2.1, 8.0.4.1, 7.2.3.1
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • rails activestorage

    From 8.1.0.beta1 · fixed in 8.1.2.1; From 8.0.0.beta1 · fixed in 8.0.4.1; fixed in 7.2.3.1

  • activestorageRubyGems

    From 8.1.0.beta1 · fixed in 8.1.2.1

  • activestorageRubyGems

    From 8.0.0.beta1 · fixed in 8.0.4.1

  • activestorageRubyGems

    fixed in 7.2.3.1

References 7

GitHub · rails/rails