CVE-2025-61771

Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, ``Rack::Multipart::Parser` stores non-file form fields (parts without a `filename`) entirely in memory as Ruby `String` objects. A single large text field in a multipart/form-data request (hundreds of megabytes or more) can consume equivalent process memory, potentially leading to out-of-memory (OOM) conditions and denial of service (DoS). Attackers can send large non-file fields to trigger excessive memory usage. Impact scales with request size and concurrency, potentially leading to worker crashes or severe garbage-collection overhead. All Rack applications processing multipart form submissions are affected. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a reasonable size cap for non-file fields (e.g., 2 MiB). Workarounds include restricting maximum request body size at the web-server or proxy layer (e.g., Nginx `client_max_body_size`) and validating and rejecting unusually large form fields at the application level.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*
cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*
cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*

History

10 Oct 2025, 16:45

Type Values Removed Values Added
CPE cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*
First Time Rack
Rack rack
References () https://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181e - () https://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181e - Patch
References () https://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29e - () https://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29e - Patch
References () https://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fd - () https://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fd - Patch
References () https://github.com/rack/rack/security/advisories/GHSA-w9pc-fmgc-vxvw - () https://github.com/rack/rack/security/advisories/GHSA-w9pc-fmgc-vxvw - Vendor Advisory

07 Oct 2025, 15:16

Type Values Removed Values Added
New CVE

Information

Published : 2025-10-07 15:16

Updated : 2025-10-10 16:45


NVD link : CVE-2025-61771

Mitre link : CVE-2025-61771

CVE.ORG link : CVE-2025-61771


JSON object : View

Products Affected

rack

  • rack
CWE
CWE-400

Uncontrolled Resource Consumption