CVE-2026-55602 http-proxy-middleware `router` host+path substring matching allows Host-header-driven backend routing bypass

http-proxy-middleware is node.js http-proxy middleware. From 0.16.0 until 2.0.10, 3.0.6, and 4.1.0, http-proxy-middleware documents router proxy-table entries as host, path, or host+path selectors, but the host+path implementation uses unanchored substring matching on attacker-controlled request...

NPM: http-proxy-middleware `router` host+path substring matching allows Host-header-driven backend routing bypass

NPM: http-proxy-middleware router host+path substring matching allows Host-header-driven backend routing bypass vulnerability discovered by ? in WordPress Npm http-proxy-middleware versions = 0.16.0, 2.0.10...