Openshift/oauth-server: openshift/oauth-server: quadratic-time dos via accept-language header underscore bypass on unauthenticated login endpoints

A flaw was found in openshift/oauth-server. The OAuth login and error page endpoints pass the unauthenticated Accept-Language header to golang.org/x/text/language.ParseAcceptLanguage() without input validation. A bypass of the CVE-2022-32149 mitigation exists: the upstream guard counts only '-' characters but the internal BCP 47 scanner aliases '_' to '-' after the guard check. An unauthenticated attacker can send a crafted Accept-Language header using '_' separators to trigger quadratic-time parsing, consuming excessive CPU and denying authentication to all cluster users.