CVE Vulnerabilities

CVE-2026-40910

Improper Authentication

Published: Apr 21, 2026 | Modified: Apr 29, 2026
CVSS 3.x
9.1
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
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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.

Weakness

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

Affected Software

NameVendorStart VersionEnd Version
FrpFatedier0.43.0 (including)0.68.1 (excluding)

Potential Mitigations

References