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Incorrect AuthorizationWeakness · CWE-863

CVE-2026-40213

HIGH · 7.4 CVSS v3.1 Published 2026-05-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OpenStack Cyborg before 16.0.1 ships with an overly permissive default policy.json using rule:allow with check_str='@' for multiple API endpoints. This policy rule unconditionally permits any request bearing a valid Keystone token, bypassing all role-based, project-based, and scope-based access controls. An authenticated user with no role assignments can trigger privileged operations such as reprogramming FPGA bitstreams on arbitrary compute nodes via agent RPC.

MitigationUpgrade to Cyborg 16.0.1 or later which replaces the permissive rule:allow defaults with proper role-based policy rules. Alternatively, manually review and update the policy.json to enforce appropriate role checks (e.g., rule:admin_or_owner) for all affected API endpoints.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Cyborg installation and version
    Run 'cyborg-manage --version' or check the package version via your system package manager (e.g., 'rpm -q python-cyborg' or 'dpkg -l python3-cyborg')
    Affected if The installed version is earlier than 16.0.1 (e.g., 16.0.0, 15.x, or earlier)
  2. Locate the Cyborg policy.json file
    Common paths include /etc/cyborg/policy.json or /var/lib/cyborg/policy.json. Check your deployment's configuration for the 'policy_file' setting in cyborg.conf under the [policy] section
    Affected if The policy.json file exists and is readable
  3. Examine policy.json for permissive rules
    Open the policy.json file and search for entries containing 'rule:allow' with 'check_str' set to '@' (the '@' symbol represents unconditional allow for any authenticated token)
    Affected if Any API endpoint entry shows "rule:allow" with "check_str": "@"
  4. Identify affected API endpoints
    Review the policy.json keys that use the permissive rule:allow. Common Cyborg API operations that may be affected include: accelerator-device-get, accelerator-device-list, deployable-get, deployable-list, bitstream-upload, bitstream-activate, bitstream-deactivate, and FPGA reprogramming operations
    Affected if Privileged operations such as bitstream/FPGA management or agent RPC calls are governed by the unconditional allow rule

You are affected if Cyborg version is earlier than 16.0.1 AND the policy.json contains "rule:allow" with "check_str": "@" for any API endpoint, allowing any authenticated Keystone user (even without roles) to perform privileged operations.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Cyborg 16.0.1 or later which replaces the permissive rule:allow defaults with proper role-based policy rules. Alternatively, manually review and update the policy.json to enforce appropriate role checks (e.g., rule:admin_or_owner) for all affected API endpoints.

Recommended fix Moderate confidence

OpenStack Cyborg 16.0.1

  1. Upgrade OpenStack Cyborg to version 16.0.1 or later
  2. After upgrading, verify that the policy.json files for affected Cyborg API endpoints no longer use 'rule:allow' with check_str='@' as the default policy
  3. Confirm that proper authorization rules are in place that enforce role-based, project-based, or scope-based checks
  4. Test that authenticated users without appropriate role assignments can no longer perform administrative actions such as reprogramming FPGA bitstreams

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-40213 in production — separate from our analysis above.

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