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, when serving files through Active Storage's proxy delivery mode, the proxy controller loads the entire requested byte range into memory before sending it. A request with a large or unbounded Range header (e.g. `bytes=0-`) could cause the server to allocate memory proportional to the file size, possibly resulting in a DoS vulnerability through memory exhaustion. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
History

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, when serving files through Active Storage's proxy delivery mode, the proxy controller loads the entire requested byte range into memory before sending it. A request with a large or unbounded Range header (e.g. `bytes=0-`) could cause the server to allocate memory proportional to the file size, possibly resulting in a DoS vulnerability through memory exhaustion. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Title Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
Weaknesses CWE-789
References
Metrics cvssV4_0

{'score': 6.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-23T23:25:23.363Z

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

Link: CVE-2026-33174

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-24T00:16:28.630

Modified: 2026-03-24T00:16:28.630

Link: CVE-2026-33174

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.