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.
Affected products
rack: rack
References2
- github.com/rack/rack/security/advisories/GHSA-625h-95r8-8xpm MitigationVendor Advisory
- github.com/rack/rack/commit/54e4ffdd5affebcb0c015cc6ae74635c083… Patch
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 49 · as of 9 November 2026
- CWE
- CWE-400CWE-770
Could this be exploited in your environment?
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