CVE-2026-33173
MEDIUM5.3EPSS 0.01%Rails Active Storage has possible content type bypass via metadata in direct uploads
Published: 3/23/2026Modified: 5/13/2026
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. ### Credit This was responsible reported by Hackerone researcher [pwnie](https://hackerone.com/pwnie)
Affected packages (2)
- Debian/railsfrom 0
- RubyGems/activestorage>= 8.1.0.beta1, < 8.1.2.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
References (11)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-33173
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-33173
- PATCHhttps://github.com/rails/rails
- WEBhttps://github.com/rails/rails/commit/707c0f1f41f067fdf96d54e99d43b28dfaae7e53
- WEBhttps://github.com/rails/rails/commit/8fcb934caadc79c8cc4ce53287046d0f67005b3e
- WEBhttps://github.com/rails/rails/commit/d9502f5214e2198245a4c1defe9cd02a7c8057d0
- WEBhttps://github.com/rails/rails/releases/tag/v7.2.3.1
- WEBhttps://github.com/rails/rails/releases/tag/v8.0.4.1
- WEBhttps://github.com/rails/rails/releases/tag/v8.1.2.1
- WEBhttps://github.com/rails/rails/security/advisories/GHSA-qcfx-2mfw-w4cg
- WEBhttps://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-33173.yml