OpenStack Cyborg <=16.0.1 Unauthenticated Policy Bypass via Rule:allow (@)
CVE-2026-40213 Published on May 7, 2026
OpenStack Cyborg before 16.0.1 uses rule:allow (check_str='@') as the default policy for multiple API endpoints. This unconditionally authorizes any request carrying a valid Keystone token regardless of roles, project membership, or scope. An authenticated user with zero role assignments can complete various actions such as reprogramming FPGA bitstreams on arbitrary compute nodes via agent RPC.
Vulnerability Analysis
CVE-2026-40213 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be low. considered to have a small impact on confidentiality and integrity and availability.
Weakness Type
What is an AuthZ Vulnerability?
The software performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.
CVE-2026-40213 has been classified to as an AuthZ vulnerability or weakness.
Affected Versions
OpenStack Cyborg:- Version 5.0.0 and below 14.0.1 is affected.
- Version 15.0.0 and below 15.0.1 is affected.
- Version 16.0.0 and below 16.0.1 is affected.