OpenStack Cyborg Flaw Allows FPGA Reprogramming via Unauthenticated API
The National Vulnerability Database (NVD) reports CVE-2026-40213, a high-severity vulnerability (CVSS 7.4) in OpenStack Cyborg versions prior to 16.0.1. The flaw stems from an insecure default policy (rule:allow, check_str='@') for multiple API endpoints. This configuration permits any request with a valid Keystone token to bypass typical role, project, and scope checks.
This misconfiguration means an authenticated user, even with zero assigned roles, can execute critical actions. Specifically, the NVD highlights the ability to reprogram FPGA bitstreams on arbitrary compute nodes through agent RPC. This isn’t just a minor bypass; it’s a direct avenue for unauthorized hardware manipulation within the OpenStack environment.
For defenders, this is a stark reminder that authentication is not authorization. The attacker’s calculus here is simple: if you can get a valid token, you own the hardware. This vulnerability turns a low-privilege user into a system controller, enabling deep system compromise and potentially persistent backdoors at the hardware level.
What This Means For You
- If your organization uses OpenStack Cyborg, particularly for managing FPGAs or other hardware accelerators, you need to immediately verify your version. Prioritize upgrading to Cyborg 16.0.1 or later. Furthermore, audit your Keystone policies for `rule:allow` or `@` directives and ensure they are tightly scoped, especially for critical infrastructure components. This isn't theoretical; this is a direct path to hardware-level compromise.
Related ATT&CK Techniques
🛡️ Detection Rules
3 rules · 6 SIEM formats3 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
OpenStack Cyborg Unauthenticated API Access for FPGA Reprogramming - CVE-2026-40213
title: OpenStack Cyborg Unauthenticated API Access for FPGA Reprogramming - CVE-2026-40213
id: scw-2026-05-07-ai-1
status: experimental
level: high
description: |
Detects unauthenticated API requests to OpenStack Cyborg endpoints related to device or driver management. The vulnerability CVE-2026-40213 allows any authenticated user with a valid Keystone token to reprogram FPGA bitstreams by exploiting the default 'rule:allow' policy on these endpoints, bypassing necessary role checks.
author: SCW Feed Engine (AI-generated)
date: 2026-05-07
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-40213/
tags:
- attack.privilege_escalation
- attack.t1078.002
logsource:
category: webserver
detection:
selection:
cs-uri|contains:
- '/v1/devices'
- '/v1/drivers'
cs-method:
- 'POST'
sc-status:
- 200
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-40213 | Auth Bypass | OpenStack Cyborg before 16.0.1 |
| CVE-2026-40213 | Privilege Escalation | OpenStack Cyborg before 16.0.1 default policy rule:allow (check_str='@') |
| CVE-2026-40213 | RCE | OpenStack Cyborg agent RPC for reprogramming FPGA bitstreams |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 08, 2026 at 01:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
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