Back to list

Rails Active Storage has possible content type bypass via metadata in direct uploads — CVE-2026-33173

GitHub · GitHub · CVE-2026-33173

ID
CVE-2026-33173
Date
Updated
Activity
Source
GitHub
Vendor
GitHub
Threat
medium
CVSS
5.3
EPSS
0.00015

Summary

### 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. ### Credit This was responsible reported by Hackerone researcher…

Product

rubygems: activestorage

What to do

General, cautious steps (verify details in the official source):

  • Review exposure and plan remediation based on risk and environment.
  • Identify affected product versions in your inventory and verify whether you are impacted.
  • Apply vendor patches/updates or recommended mitigations as soon as available.
  • Read the official advisory for exact affected versions and remediation steps.

Official advisory

Related advisories