GHSA-MQXV-9RM6-W8QC Ech0: ParseAcceptLanguage `_` separator bypass enables ~70x CPU amplification via Accept-Language header in i18n.Middleware

Summary Ech0's i18n middleware runs on every HTTP request and constructs a fresh goi18n.Localizer from the raw Accept-Language header without imposing any size or shape filter. goi18n.NewLocalizer calls golang.org/x/text/language.ParseAcceptLanguage on the value internally. The underlying parser...