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.
Published: 2025-09-25
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4357-1 ruby-rack security update
EUVD EUVD EUVD-2025-31103 Rack has an unsafe default in Rack::QueryParser allows params_limit bypass via semicolon-separated parameters
Github GHSA Github GHSA GHSA-625h-95r8-8xpm Rack has an unsafe default in Rack::QueryParser allows params_limit bypass via semicolon-separated parameters
Ubuntu USN Ubuntu USN USN-7784-1 Rack vulnerability
History

Fri, 10 Oct 2025 16:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*

Tue, 07 Oct 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


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 : Analyzed

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

Modified: 2025-10-10T16:43:14.337

Link: CVE-2025-59830

cve-icon Redhat

Severity : Important

Publid Date: 2025-09-25T14:37:06Z

Links: CVE-2025-59830 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-09-26T11:35:51Z

Weaknesses