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.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/rack/rack/commit/54e4ffdd5affebcb0c015cc6ae74635c0831ed71 Patch
- https://github.com/rack/rack/security/advisories/GHSA-625h-95r8-8xpm Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · rackNVD modified 2026-10-19 16:10
Affected (CPE criteria) 1
cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*