Red Hat: CVE-2025-59830: rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters (Multiple Advisories)

An unsafe default behavior in Rack::QueryParser allows bypass of the params_limit parameter count restriction when query string parameters are delimited by semicolons (;) rather than ampersands (&). The parser counts only & when enforcing the limit, while still splitting on both & and ;. As a result, an attacker can supply a crafted HTTP query using ; delimiters to exceed the intended parameter count, potentially causing performance degradation or exhaustion of resources (denial of service).