CVE-2025-61919

Rack is a modular Ruby web server interface. Prior to versions 2.2.20, 3.1.18, and 3.2.3, `Rack::Request#POST` reads the entire request body into memory for `Content-Type: application/x-www-form-urlencoded`, calling `rack.input.read(nil)` without enforcing a length or cap. Large request bodies can therefore be buffered completely into process memory before parsing, leading to denial of service (DoS) through memory exhaustion. Users should upgrade to Rack version 2.2.20, 3.1.18, or 3.2.3, anu of which enforces form parameter limits using `query_parser.bytesize_limit`, preventing unbounded reads of `application/x-www-form-urlencoded` bodies. Additionally, enforce strict maximum body size at the proxy or web server layer (e.g., Nginx `client_max_body_size`, Apache `LimitRequestBody`).

Affected products

Almalinux, Apache, Centos, Debian, Linuxmint, Nginx, Rack, Red Hat

Rack

< 2.2.20, 3.1.18, 3.2.3

Fix

Available

CVSS 3.1

7.5 HIGH

EPSS

0.6% (46th percentile)

Weakness

CWE-400

NVD status

Analyzed

Published

2025-10-10

No exploit for CVE-2025-61919 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.