Execution Path Analysis: The GPUStack authentication bypass vulnerability (CVE-2026-102895) exploits the trust placed in the 'X-Gpustack-Real-IP' header. Attackers can spoof this header to appear as if requests originate from a trusted source, such as the loopback address, thereby bypassing authentication mechanisms. This vulnerability is particularly concerning for environments running AI workloads, as it allows unauthorized access to sensitive computational resources.

# Production Sigma Detection Rule: Ingress Authorization Bypass & Boundary Interception
title: Suspicious Ingress Authentication Bypass & Zero Trust Boundary Violation
id: 7c8f4201-d82e-4a61-b958-d2cf5f7682e4
status: stable
description: Detects abnormal API ingress authorization attempts bypassing IAM session boundaries and zero-trust edge filters.
logsource:
  category: webserver
  product: enterprise_ingress
detection:
  selection:
    http_method: 'POST'
    uri_path|contains:
      - '/api/v1/auth/'
      - '/oauth/token'
      - '/internal/service/'
  filter_authorized:
    status: 200
    http_user_agent|contains: 'ApprovedEdgeProxy'
  condition: selection and not filter_authorized
falsepositives:
  - Legitimate administrative gateway updates
level: high
tags:
  - attack.initial_access
  - attack.t1190

Choke Point Mitigation: Implementing structural Zero Trust principles is essential to mitigate this vulnerability. Organizations should enforce strict validation of header values and employ Web Application Firewalls (WAFs) to intercept and block unauthorized requests. Additionally, deploying network segmentation and access control lists (ACLs) can prevent unauthorized lateral movement within the network. Regular audits and updates to the GPUStack software are recommended to ensure compliance with security best practices.