Rack is a modular Ruby web server interface. Prior to version 2.2.18, Rack::QueryParser enforces its params_limit only for parameters separated by &, while still splitting on both & and ;. As a result, attackers could use ; separators to bypass the parameter count limit and submit more parameters than intended. Applications or middleware that directly invoke Rack::QueryParser with its default configuration (no explicit delimiter) could be exposed to increased CPU and memory consumption. This can be abused as a limited denial-of-service vector. This issue has been patched in version 2.2.18.
History

Fri, 26 Sep 2025 11:45:00 +0000

Type Values Removed Values Added
First Time appeared Rack
Rack rack
Vendors & Products Rack
Rack rack

Thu, 25 Sep 2025 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 25 Sep 2025 15:00:00 +0000

Type Values Removed Values Added
Description Rack is a modular Ruby web server interface. Prior to version 2.2.18, Rack::QueryParser enforces its params_limit only for parameters separated by &, while still splitting on both & and ;. As a result, attackers could use ; separators to bypass the parameter count limit and submit more parameters than intended. Applications or middleware that directly invoke Rack::QueryParser with its default configuration (no explicit delimiter) could be exposed to increased CPU and memory consumption. This can be abused as a limited denial-of-service vector. This issue has been patched in version 2.2.18.
Title Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters
Weaknesses CWE-400
CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-09-25T16:16:15.255Z

Reserved: 2025-09-22T14:34:03.471Z

Link: CVE-2025-59830

cve-icon Vulnrichment

Updated: 2025-09-25T16:16:11.658Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-09-25T15:16:13.780

Modified: 2025-09-26T14:32:53.583

Link: CVE-2025-59830

cve-icon Redhat

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