CVE-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` 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.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/rails/rails/commit/707c0f1f41f067fdf96d54e99d43b28dfaae7e53	Patch
https://github.com/rails/rails/commit/8fcb934caadc79c8cc4ce53287046d0f67005b3e	Patch
https://github.com/rails/rails/commit/d9502f5214e2198245a4c1defe9cd02a7c8057d0	Patch
https://github.com/rails/rails/releases/tag/v7.2.3.1	Release Notes
https://github.com/rails/rails/releases/tag/v8.0.4.1	Release Notes
https://github.com/rails/rails/releases/tag/v8.1.2.1	Release Notes
https://github.com/rails/rails/security/advisories/GHSA-qcfx-2mfw-w4cg	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:rubyonrails:rails::::::::
	cpe:2.3:a:rubyonrails:rails::::::::
	cpe:2.3:a:rubyonrails:rails::::::::

History

No history.

Information

Published : 2026-03-24 00:16

Updated : 2026-03-24 17:56

NVD link : CVE-2026-33173

Mitre link : CVE-2026-33173

CVE.ORG link : CVE-2026-33173

JSON object : View

Products Affected

rubyonrails

rails

CWE

CWE-925

Improper Verification of Intent by Broadcast Receiver

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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."}, {"lang": "es", "value": "Active Storage permite a los usuarios adjuntar archivos locales y en la nube en aplicaciones Rails. Antes de las versiones 8.1.2.1, 8.0.4.1 y 7.2.3.1, 'DirectUploadsController' acepta metadatos arbitrarios del cliente y los persiste en el blob. Debido a que indicadores internos como 'identified' y 'analyzed' se almacenan en el mismo hash de metadatos, un cliente de carga directa puede establecer estos indicadores para omitir la detecci\u00f3n y el an\u00e1lisis MIME. Esto permite a un atacante cargar contenido arbitrario mientras declara un 'content_type' seguro, eludiendo cualquier validaci\u00f3n que dependa de la identificaci\u00f3n autom\u00e1tica del tipo de contenido de Active Storage. 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