CVE-2026-40213: OpenStack Cyborg uses rule Allow (check_str='@') As The Default Vulnerability

HIGH
Advisory Identifier: GHSA-mm7j-mhhj-hj36
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CVSS 7.4
CWE-863
Published
Advisory Summary

CVE-2026-40213 is a HIGH (CVSS 7.4) allow (check_str='@') as the default vulnerability (CWE-863: Incorrect Authorization) affecting OpenStack Cyborg uses rule libraries in the PyPI ecosystem. The issue involves allow (check_str='@') as the default policy for multiple api endpoints. Remediation is available by upgrading affected packages to version 16.0.1.

CVE-2026-40213 at a Glance

CVE Identifier CVE-2026-40213
GHSA Identifier GHSA-mm7j-mhhj-hj36
Severity HIGH
CVSS v3.1 Base Score 7.4
CWE Classification CWE-863: Incorrect Authorization
Affected Product OpenStack Cyborg uses rule
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2026-40213

To remediate this vulnerability, upgrade all affected OpenStack Cyborg uses rule dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

openstack-cyborg fixed: 16.0.1 
pip install openstack-cyborg>=16.0.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show openstack-cyborg

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-40213, inspect your installed packages using pip:

pip show openstack-cyborg

Analyze the terminal output to locate any version of OpenStack Cyborg uses rule in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 16.0.1), your application is affected.

Note: The pip show openstack-cyborg command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In OpenStack Cyborg uses rule, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-40213 Affected OpenStack Cyborg uses rule Versions

1 component(s)
Fixed Versions:
16.0.1
Product / Package Ecosystem Affected Versions Fixed Version
openstack-cyborg
pypi/openstack-cyborg
PyPI
< 16.0.1
16.0.1

References

NVD — CVE-2026-40213 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40213
bugs.launchpad.net/openstack-cyborg/+b... WEB
https://bugs.launchpad.net/openstack-cyborg/+bug/2143263
OpenStack Cyborg uses rule Source Repository REPOSITORY
https://github.com/openstack/cyborg
OpenStack Cyborg uses rule Security Information SECURITY
https://security.openstack.org/ossa/OSSA-2026-011.html
OpenStack Cyborg uses rule Security Information SECURITY
https://www.openwall.com/lists/oss-security/2026/05/07/6

Frequently Asked Questions

What is CVE-2026-40213?
CVE-2026-40213 is a security vulnerability in OpenStack Cyborg uses rule involving allow (check_str='@') as the default policy for multiple API endpoints under CWE-863: Incorrect Authorization.
Which OpenStack Cyborg uses rule versions are affected?
Affected versions include releases prior to 16.0.1 across affected packages: openstack-cyborg.
What version fixes CVE-2026-40213?
Upgrading to 16.0.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is openstack-cyborg affected?
Yes, openstack-cyborg is affected in releases prior to 16.0.1. Upgrade your dependency to 16.0.1 or later.
What is the CVSS score of CVE-2026-40213?
CVE-2026-40213 has a CVSS v3.1 base score of 7.4 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L.
What CWE is associated with CVE-2026-40213?
CVE-2026-40213 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check PyPI dependencies for CVE-2026-40213?
Run the dependency tree command: 'pip show openstack-cyborg'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mm7j-mhhj-hj36",
  "modified" : "2026-05-13T01:37:14Z",
  "published" : "2026-05-08T00:31:33Z",
  "aliases" : [ "CVE-2026-40213" ],
  "summary" : "OpenStack Cyborg uses rule:allow (check_str='@') as the default policy for multiple API endpoints",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "openstack-cyborg"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "16.0.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40213"
  }, {
    "type" : "WEB",
    "url" : "https://bugs.launchpad.net/openstack-cyborg/+bug/2143263"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openstack/cyborg"
  }, {
    "type" : "WEB",
    "url" : "https://security.openstack.org/ossa/OSSA-2026-011.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.openwall.com/lists/oss-security/2026/05/07/6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-13T01:37:14Z",
    "nvd_published_at" : "2026-05-07T22:16:34Z"
  }
}