CVE-2026-42998: Keystone OpenStack Keystone Doesn't Verify That Vulnerability

MODERATE
Advisory Identifier: GHSA-8f8m-wrvr-wcvf
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CVSS 6.0
CWE-863
Published
Advisory Summary

CVE-2026-42998 is a MODERATE (CVSS 6.0) openstack keystone doesn't verify that vulnerability (CWE-863: Incorrect Authorization) affecting Keystone libraries in the PyPI ecosystem. The issue involves openstack keystone doesn't verify that the user supplied in the authentication request matches the owner of the application credential. Remediation is available by upgrading affected packages to version 27.0.2, 28.0.2, 29.0.2.

CVE-2026-42998 at a Glance

CVE Identifier CVE-2026-42998
GHSA Identifier GHSA-8f8m-wrvr-wcvf
Severity MODERATE
CVSS v3.1 Base Score 6.0
CWE Classification CWE-863: Incorrect Authorization
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-2026-42998

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: 27.0.2 
pip install keystone>=27.0.2
keystone fixed: 28.0.2 
pip install keystone>=28.0.2
keystone fixed: 29.0.2 
pip install keystone>=29.0.2
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-2026-42998, 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 27.0.2), 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-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 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. The Keystone application credential authentication plugin does not verify that the user supplied in the authentication request matches the owner of the application credential. An attacker can authenticate with their own application credential ID and secret while specifying a different user's name and domain in the request body. Keystone issues a token attributed to the victim user. The impersonated token is project-scoped and carries the intersection of the application credential's roles and the victim's actual roles on the project. This enables audit evasion, reading the victim's credentials, and acting as the victim within shared projects.

CVE-2026-42998 Affected Keystone Versions

3 component(s)
Fixed Versions:
27.0.228.0.229.0.2
Product / Package Ecosystem Affected Versions Fixed Version
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
keystone
pypi/keystone
PyPI
≥ 29.0.0
< 29.0.2
29.0.2

References

NVD — CVE-2026-42998 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42998
bugs.launchpad.net/keystone/+bug/21484... WEB
https://bugs.launchpad.net/keystone/+bug/2148477
Keystone Source Repository REPOSITORY
https://github.com/openstack/keystone
Keystone Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/keystone/PYSEC-2026-599.yaml
Keystone Security Information SECURITY
https://security.openstack.org/ossa/OSSA-2026-015.html

Frequently Asked Questions

What is CVE-2026-42998?
CVE-2026-42998 is a security vulnerability in Keystone involving OpenStack Keystone doesn't verify that the user supplied in the authentication request matches the owner of the application credential under CWE-863: Incorrect Authorization.
Which Keystone versions are affected?
Affected versions include releases prior to 27.0.2, 28.0.2, 29.0.2 across affected packages: keystone.
What version fixes CVE-2026-42998?
Upgrading to 27.0.2, 28.0.2, 29.0.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is keystone affected?
Yes, keystone is affected in releases prior to 27.0.2, 28.0.2, 29.0.2. Upgrade your dependency to 27.0.2, 28.0.2, 29.0.2 or later.
What is the CVSS score of CVE-2026-42998?
CVE-2026-42998 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-2026-42998?
CVE-2026-42998 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-2026-42998?
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-8f8m-wrvr-wcvf",
  "modified" : "2026-07-02T17:43:19Z",
  "published" : "2026-05-28T21:32:02Z",
  "aliases" : [ "CVE-2026-42998" ],
  "summary" : "OpenStack Keystone doesn't verify that the user supplied in the authentication request matches the owner of the application credential",
  "details" : "An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone application credential authentication plugin does not verify that the user supplied in the authentication request matches the owner of the application credential. An attacker can authenticate with their own application credential ID and secret while specifying a different user's name and domain in the request body. Keystone issues a token attributed to the victim user. The impersonated token is project-scoped and carries the intersection of the application credential's roles and the victim's actual roles on the project. This enables audit evasion, reading the victim's credentials, and acting as the victim within shared projects.",
  "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-2026-42998"
  }, {
    "type" : "WEB",
    "url" : "https://bugs.launchpad.net/keystone/+bug/2148477"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openstack/keystone"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/keystone/PYSEC-2026-599.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://security.openstack.org/ossa/OSSA-2026-015.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-02T17:43:19Z",
    "nvd_published_at" : "2026-05-28T19:16:37Z"
  }
}