CVE-2026-33173
published 2026-03-24CVE-2026-33173: 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`…
PriorityP434medium5.3CVSS 3.1
AVNACLPRNUINSUCNILAN
EPSS
0.39%
31.6th percentile
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
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | rails | — | — |
| rails | activestorage | < 7.2.3.1 | 7.2.3.1 |
| rails | activestorage | — | — |
| rails | activestorage | — | — |
| rails | activestorage | >= 0 < 7.2.3.1 | 7.2.3.1 |
| rails | activestorage | >= 8.0.0.beta1 < 8.0.4.1 | 8.0.4.1 |
| rails | activestorage | >= 8.1.0.beta1 < 8.1.2.1 | 8.1.2.1 |
| rubyonrails | rails | < 7.2.3.1 | 7.2.3.1 |
| rubyonrails | rails | >= 8.0.0 < 8.0.4.1 | 8.0.4.1 |
| rubyonrails | rails | >= 8.1.0 < 8.1.2.1 | 8.1.2.1 |
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
nvdv4.05.3MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
osv5.3MEDIUM
vendor_debian5.3MEDIUM
vendor_redhat5.3MEDIUM
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Red Hat
Rails: Active Storage: Rails Active Storage: Content type bypass via arbitrary metadata in direct uploads
vendor_redhat·2026-03-23·CVSS 5.3
CVE-2026-33173 [MEDIUM] CWE-1287 Rails: Active Storage: Rails Active Storage: Content type bypass via arbitrary metadata in direct uploads
Rails: Active Storage: Rails Active Storage: Content type bypass via arbitrary metadata in direct uploads
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.
A flaw was found in Rails Active Storage. A rem
Debian
CVE-2026-33173: rails - Active Storage allows users to attach cloud and local files in Rails application...
vendor_debian·2026·CVSS 5.3
CVE-2026-33173 [MEDIUM] CVE-2026-33173: rails - Active Storage allows users to attach cloud and local files in Rails application...
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.
Scope: local
bookworm: open
bullseye: open
forky: open
sid: open
trixie: open
OSV
CVE-2026-33173: Active Storage allows users to attach cloud and local files in Rails applications
osv·2026-03-24·CVSS 5.3
CVE-2026-33173 [MEDIUM] CVE-2026-33173: Active Storage allows users to attach cloud and local files in Rails applications
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.
OSV
Rails Active Storage has possible content type bypass via metadata in direct uploads
osv·2026-03-23
CVE-2026-33173 [MEDIUM] Rails Active Storage has possible content type bypass via metadata in direct uploads
Rails Active Storage has possible content type bypass via metadata in direct uploads
### 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.
GHSA
Rails Active Storage has possible content type bypass via metadata in direct uploads
ghsa·2026-03-23
CVE-2026-33173 [MEDIUM] CWE-925 Rails Active Storage has possible content type bypass via metadata in direct uploads
Rails Active Storage has possible content type bypass via metadata in direct uploads
### 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.
No detection rules found.
No public exploits indexed.
https://github.com/rails/rails/commit/707c0f1f41f067fdf96d54e99d43b28dfaae7e53https://github.com/rails/rails/commit/8fcb934caadc79c8cc4ce53287046d0f67005b3ehttps://github.com/rails/rails/commit/d9502f5214e2198245a4c1defe9cd02a7c8057d0https://github.com/rails/rails/releases/tag/v7.2.3.1https://github.com/rails/rails/releases/tag/v8.0.4.1https://github.com/rails/rails/releases/tag/v8.1.2.1https://github.com/rails/rails/security/advisories/GHSA-qcfx-2mfw-w4cg
2026-03-24
Published