---
id: CVE-2026-42999
aliases:
  - GHSA-2r23-2g6v-2m5f
  - PYSEC-2026-600
title: OpenStack Keystone has an Authorization Bypass
summary: OpenStack Keystone has an Authorization Bypass
severity: medium
cvss: 6
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L'
vendor: keystone
product: keystone
ecosystem: pip
affected:
  - 'keystone >= 14.0.0, < 27.0.2'
  - 'keystone >= 28.0.0, < 28.0.2'
  - 'keystone >= 29.0.0, < 29.0.2'
patched:
  - keystone 27.0.2
  - keystone 28.0.2
  - keystone 29.0.2
published: '2026-05-28'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:51:04.100486004Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-2r23-2g6v-2m5f'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-42999'
  - url: 'https://access.redhat.com/security/cve/CVE-2026-42999'
  - url: 'https://bugs.launchpad.net/keystone/+bug/2148398'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2482840'
  - url: 'https://github.com/openstack/keystone'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/keystone/PYSEC-2026-600.yaml
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42999.json
  - url: 'https://security.openstack.org/ossa/OSSA-2026-015.html'
tags:
  - osv
  - pip
epss: 0.00329
epssPercentile: 0.2632
ingestedAt: '2026-07-08T18:25:44.604Z'
---

## Overview

An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone RBAC policy enforcer in enforce_call unconditionally merges the raw JSON request body into the policy enforcement dictionary via policy_dict.update(json_input.copy()), overwriting trusted target data that was previously set from database lookups. Because flask.request.get_json is called with force=True, this works regardless of Content-Type or HTTP method. Any authenticated user can inject arbitrary policy target attributes (e.g., user_id, project_id) into the request body to bypass RBAC checks and perform unauthorized operations on resources belonging to other users or projects. This was introduced in commit 5ea59f52 (Rocky/14.0.0).

## Affected packages

- `keystone >= 14.0.0, < 27.0.2`
- `keystone >= 28.0.0, < 28.0.2`
- `keystone >= 29.0.0, < 29.0.2`

## Remediation

Upgrade to a patched release:

- `keystone 27.0.2`
- `keystone 28.0.2`
- `keystone 29.0.2`