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.
History

Tue, 24 Mar 2026 18:00:00 +0000

Type Values Removed Values Added
First Time appeared Rubyonrails
Rubyonrails rails
CPEs cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*
Vendors & Products Rubyonrails
Rubyonrails rails
Metrics cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}


Tue, 24 Mar 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 24 Mar 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1287
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L'}

threat_severity

Moderate


Tue, 24 Mar 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Rails
Rails activestorage
Vendors & Products Rails
Rails activestorage

Tue, 24 Mar 2026 02:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Rails Active Storage has possible content type bypass via metadata in direct uploads
Weaknesses CWE-925
References
Metrics cvssV4_0

{'score': 5.3, 'vector': '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-24T15:12:50.569Z

Reserved: 2026-03-17T22:16:36.719Z

Link: CVE-2026-33173

cve-icon Vulnrichment

Updated: 2026-03-24T14:14:26.157Z

cve-icon NVD

Status : Analyzed

Published: 2026-03-24T00:16:28.457

Modified: 2026-03-24T17:56:09.113

Link: CVE-2026-33173

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-23T23:21:29Z

Links: CVE-2026-33173 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-03-25T20:36:05Z