{"cve":"CVE-2026-55602","nvd":{"published":"2026-06-22T18:16:48.073","modified":"2026-10-25T23:10:00.167","status":"Analyzed","description":"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 metadata. As a result, a crafted Host header that is only a superstring match for a configured host+path key can still route a request to an unintended backend. This vulnerability is fixed in 2.0.10, 3.0.6, and 4.1.0.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","score":6.9},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","score":8.6},"cwes":["CWE-20","CWE-187"],"references":["https://github.com/chimurai/http-proxy-middleware/security/advisories/GHSA-64mm-vxmg-q3vj","https://github.com/chimurai/http-proxy-middleware/security/advisories/GHSA-64mm-vxmg-q3vj"],"products":["chimurai:http-proxy-middleware"],"source":"nvd","synced_at":"2026-10-25T23:44:33.281319194+00:00"},"epss":{"cve":"CVE-2026-55602","score":0.00378,"percentile":0.31461,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-64mm-vxmg-q3vj","url":"https://osv.dev/vulnerability/GHSA-64mm-vxmg-q3vj","summary":"http-proxy-middleware `router` host+path substring matching allows Host-header-driven backend routing bypass","modified":"2026-09-10T03:50:48.473416745Z","packages":[{"ecosystem":"npm","name":"http-proxy-middleware","purl":"pkg:npm/http-proxy-middleware","ranges":[">=3.0.0 <3.0.6"],"fixed":["3.0.6"]},{"ecosystem":"npm","name":"http-proxy-middleware","purl":"pkg:npm/http-proxy-middleware","ranges":[">=4.0.0 <4.1.0"],"fixed":["4.1.0"]},{"ecosystem":"npm","name":"http-proxy-middleware","purl":"pkg:npm/http-proxy-middleware","ranges":[">=0.16.0 <2.0.10"],"fixed":["2.0.10"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}