Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M

CVE-2026-40910frp: Authentication bypass in frp HTTP vhost routing when routeByHTTPUser is used for access control

Medium 6.5

In plain English

A medium-severity improper authentication in frp from fatedier. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 80.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/fatedier/frp0.68.1GHSA-pq96-pwvg-vrr9
Gogithub.com/fatedier/frp0.68.1GO-2026-5549

Affected products (as reported)

VendorProductVersions
fatedier frp < 0.68.1

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

References