This vulnerability involves an authentication bypass via a custom HTTP header "Grpc-Metadata-USER". An attacker who is already authenticated can spoof the identity of another user by including this header in their requests, effectively impersonating that user. This can lead to a complete account takeover, escalating privileges from a low-level user to an administrator. The vulnerability is classified under CWE-290 (Authentication Bypass) and has a CVSS 3.1 base score of 9.6, indicating critical severity with network attack vector, low attack complexity, low privileges required, no user interaction, and high impact on confidentiality and integrity.

An attacker with valid authentication credentials can impersonate any other GUI user by manipulating the "Grpc-Metadata-USER" header. This enables privilege escalation from a low-privileged user to an administrator, resulting in a full account takeover. The confidentiality and integrity of the system are severely impacted, but availability is not affected.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to trusted users only and monitor for suspicious use of the "Grpc-Metadata-USER" header in requests. Avoid relying solely on this header for user identity verification.