CVE-2026-43000: Keystone OpenStack Keystone Has An Incorrect Vulnerability

MODERATE
Advisory Identifier: GHSA-q623-f4j4-p4xj
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CVSS 6.0
CWE-266 CWE-863
Published
Advisory Summary

CVE-2026-43000 is a MODERATE (CVSS 6.0) openstack keystone has an incorrect vulnerability (CWE-266: Incorrect Privilege Assignment) affecting Keystone libraries in the PyPI ecosystem. The issue involves openstack keystone has an incorrect authorization issue. Remediation is available by upgrading affected packages to version 29.0.2, 27.0.2, 28.0.2.

CVE-2026-43000 at a Glance

CVE Identifier CVE-2026-43000
GHSA Identifier GHSA-q623-f4j4-p4xj
Severity MODERATE
CVSS v3.1 Base Score 6.0
CWE Classification CWE-266: Incorrect Privilege Assignment
Affected Product Keystone
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.0

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

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
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-2026-43000

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

keystone fixed: 29.0.2 
pip install keystone>=29.0.2
keystone fixed: 27.0.2 
pip install keystone>=27.0.2
keystone fixed: 28.0.2 
pip install keystone>=28.0.2
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 keystone

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-43000, inspect your installed packages using pip:

pip show keystone

Analyze the terminal output to locate any version of Keystone in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 29.0.2), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-266: Incorrect Privilege Assignment, where a product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor. In Keystone, 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

An issue was discovered in OpenStack Keystone before 29.0.2. When combined with an application credential impersonation vulnerability, an attacker with the member role on a project can escalate to admin by chaining unrestricted application credentials with Keystone trusts. The impersonated token carries the victim's identity, which passes the trustor validation check. Keystone then validates the delegated roles against the victim's actual role assignments in the database, not the roles on the requesting token. This allows the attacker to create a trust delegating the victim's admin role to themselves. The trust persists independently, and additional trusts and application credentials can be created to maintain access. All actions are logged under the victim's identity.

CVE-2026-43000 Affected Keystone Versions

3 component(s)
Fixed Versions:
29.0.227.0.228.0.2
Product / Package Ecosystem Affected Versions Fixed Version
keystone
pypi/keystone
PyPI
≥ 29.0.0
< 29.0.2
29.0.2
keystone
pypi/keystone
PyPI
≥ 14.0.0
< 27.0.2
27.0.2
keystone
pypi/keystone
PyPI
≥ 28.0.0
< 28.0.2
28.0.2

References

NVD — CVE-2026-43000 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-43000
Keystone Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-43000
bugs.launchpad.net/keystone/+bug/21484... WEB
https://bugs.launchpad.net/keystone/+bug/2148477
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2482826
Keystone Source Repository REPOSITORY
https://github.com/openstack/keystone
Keystone Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/keystone/PYSEC-2026-601.yaml
Keystone Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43000.json
Keystone Security Information SECURITY
https://security.openstack.org/ossa/OSSA-2026-015.html

Frequently Asked Questions

What is CVE-2026-43000?
CVE-2026-43000 is a security vulnerability in Keystone involving OpenStack Keystone has an Incorrect Authorization issue under CWE-266: Incorrect Privilege Assignment.
Which Keystone versions are affected?
Affected versions include releases prior to 29.0.2, 27.0.2, 28.0.2 across affected packages: keystone.
What version fixes CVE-2026-43000?
Upgrading to 29.0.2, 27.0.2, 28.0.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is keystone affected?
Yes, keystone is affected in releases prior to 29.0.2, 27.0.2, 28.0.2. Upgrade your dependency to 29.0.2, 27.0.2, 28.0.2 or later.
What is the CVSS score of CVE-2026-43000?
CVE-2026-43000 has a CVSS v3.1 base score of 6.0 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L.
What CWE is associated with CVE-2026-43000?
CVE-2026-43000 is classified under CWE-266: Incorrect Privilege Assignment (A product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.).
How can I check PyPI dependencies for CVE-2026-43000?
Run the dependency tree command: 'pip show keystone'. 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-q623-f4j4-p4xj",
  "modified" : "2026-07-02T17:44:16Z",
  "published" : "2026-05-28T21:32:02Z",
  "aliases" : [ "CVE-2026-43000" ],
  "summary" : "OpenStack Keystone has an Incorrect Authorization issue",
  "details" : "An issue was discovered in OpenStack Keystone before 29.0.2. When combined with an application credential impersonation vulnerability, an attacker with the member role on a project can escalate to admin by chaining unrestricted application credentials with Keystone trusts. The impersonated token carries the victim's identity, which passes the trustor validation check. Keystone then validates the delegated roles against the victim's actual role assignments in the database, not the roles on the requesting token. This allows the attacker to create a trust delegating the victim's admin role to themselves. The trust persists independently, and additional trusts and application credentials can be created to maintain access. All actions are logged under the victim's identity.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "keystone"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "14.0.0"
      }, {
        "fixed" : "27.0.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "keystone"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "28.0.0"
      }, {
        "fixed" : "28.0.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "keystone"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "29.0.0"
      }, {
        "fixed" : "29.0.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-43000"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-43000"
  }, {
    "type" : "WEB",
    "url" : "https://bugs.launchpad.net/keystone/+bug/2148477"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2482826"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openstack/keystone"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/keystone/PYSEC-2026-601.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43000.json"
  }, {
    "type" : "WEB",
    "url" : "https://security.openstack.org/ossa/OSSA-2026-015.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-266", "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-02T17:44:16Z",
    "nvd_published_at" : "2026-05-28T19:16:37Z"
  }
}