CVE-2026-40910
frp: Authentication bypass in frp HTTP vhost routing when routeByHTTPUser is used for access control
frp is a fast reverse proxy. From 0.43.0 to 0.68.0, frp contains an authentication bypass in the HTTP vhost routing path when routeByHTTPUser is used as part of access control. In proxy-style requests, the routing logic uses the username from Proxy-Authorization to select the routeByHTTPUser backend, while the access control check uses credentials from the regular Authorization header. As a result, an attacker who can reach the HTTP vhost entrypoint and knows or can guess the protected routeByHTTPUser value may access a backend protected by httpUser / httpPassword even with an incorrect Proxy-Authorization password. This issue affects deployments that explicitly use routeByHTTPUser. It does not affect ordinary HTTP proxies that do not use this feature. This vulnerability is fixed in 0.68.1.
- Affected
- fatedier · frp
- CVSS v3.1 NVD
- 9.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS v3.1 GITHUB
- 6.5 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - EPSS
- 0.40% chance of exploitation in the next 30 days, 32nd percentile
- Published
- 2026-04-21