Auth bypass in Nezhahq Nezha

CVE-2026-46717

Nezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. From version 1.4.0 to before version 2.0.8, nezha's dashboard supports two user roles: RoleAdmin (Role==0) and RoleMember (Role==1). The notification routes POST /api/v1/notification and PATCH /api/v1/notification/:id are wired through commonHandler rather than adminHandler — so a RoleMember user can call them. These handlers synchronously Send() an HTTP request to a user-controlled URL and reflect the entire response body (no size limit) back to the caller on any non-2xx response. This issue has been patched in version 2.0.8.

Vulnerability class: Broken Access Control

EPSS: 0.003 (19.0th percentile) — read the EPSS interpretation.