CVE-2025-59830 — Uncontrolled Resource Consumption in Rack

CWE-400 — Uncontrolled Resource ConsumptionCWE-770 — Allocation of Resources Without Limits or Throttling9 documents6 sources
Severity
7.5HIGHNVD
EPSS
0.1%
top 78.89%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
RackDebian Ruby-rack
Timeline
PublishedSep 25
Latest updateJan 14

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…

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages3 packages

▶debiandebian/ruby-rack< ruby-rack 2.2.20-0+deb12u1 (bookworm)
▶NVDrack/rack< 2.2.18
▶RubyGemsrack/rack< 2.2.18

Patches

Patch: github.com ↗

🔴Vulnerability Details

4
OSV
ruby-rack vulnerabilities↗2026-01-14
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OSV
Rack has an unsafe default in Rack::QueryParser allows params_limit bypass via semicolon-separated parameters↗2025-09-25
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OSV
CVE-2025-59830: Rack is a modular Ruby web server interface↗2025-09-25
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GHSA
Rack has an unsafe default in Rack::QueryParser allows params_limit bypass via semicolon-separated parameters↗2025-09-25
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📋Vendor Advisories

4
Ubuntu
Rack vulnerabilities↗2026-01-14
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Ubuntu
Rack vulnerability↗2025-09-29
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Red Hat
rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters↗2025-09-25
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Debian
CVE-2025-59830: ruby-rack - Rack is a modular Ruby web server interface. Prior to version 2.2.18, Rack::Quer...↗2025
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