CVE-2026-40910CRITICAL 9.1EPSS p18.3%
CVE-2026-40910CVE-2026-40910
Description
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.
Scoring
| CVSS 3.1 | 9.1 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| EPSS | 0.27% probability of exploitation · percentile 18.3% · 2026-06-19T12:03:05Z |
| Published | 2026-04-21 |
| Last modified | 2026-04-29 |
Underlying weaknesses· 1
References
1
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Improper Authenticationcwe-287 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.