CVE-2026-55602
CVE-2026-55602 · http-proxy-middleware `router` host+path substring matching allows Host-header-driven backend routing bypass
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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 6.9 · Medium · EPSS 0.4% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
http-proxy-middleware
- Versions
- >= 4.0.0, < 4.1.0: Affected
- >= 3.0.0, < 3.0.6: Affected
- >= 0.16.0, < 2.0.10: Affected
No fix published
http-proxy-middleware npm
- Affected ranges
- SEMVER: ≥ 3.0.0, < 3.0.6
Update to 3.0.6
http-proxy-middleware npm
- Affected ranges
- SEMVER: ≥ 4.0.0, < 4.1.0
Update to 4.1.0
http-proxy-middleware npm
- Affected ranges
- SEMVER: ≥ 0.16.0, < 2.0.10
Update to 2.0.10