CVE-2026-42999 OpenStack Keystone has an Authorization Bypass
Authenticated users can bypass RBAC checks by injecting policy attributes into request bodies, allowing unauthorized access to other users' resources.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42999?
CVE-2026-42999 is a medium-severity missing authorization vulnerability in OpenStack Keystone, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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).
Which versions are affected by CVE-2026-42999?
7 open source packages ship an affected version, including keystone. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
keystone PyPI | From 14.0.0 | 27.0.2, 28.0.2, 29.0.2 |
keystone PyPI | From 14.0.0 | 27.0.2 |
keystone PyPI | From 14.0.0 | 27.0.2 |
keystone PyPI | From 28.0.0 | 28.0.2 |
keystone PyPI | From 28.0.0 | 28.0.2 |
keystone PyPI | From 29.0.0 | 29.0.2 |
1 more packages
keystone PyPI | From 29.0.0 | 29.0.2 |
Products include Openstack Keystone.
How do I fix CVE-2026-42999?
Upgrade keystone to a fixed version for your release line: 27.0.2, 28.0.2 or 29.0.2.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-42999 being exploited?
There is no known exploitation of CVE-2026-42999 in the wild and no public exploit code.
Other vulnerabilities in OpenStack Keystone
- CVE-2020-12690 Insufficient Session Expiration in OpenStack Keystone
- CVE-2019-19687 OpenStack Keystone Credential Leakage
- CVE-2026-43001 OpenStack Keystone has an Incorrect Authorization Issue
- CVE-2014-2828 OpenStack Identity (Keystone) DoS through V3 API authentication chaining
- CVE-2021-38155 OpenStack Keystone allows information disclosure during account locking
Sources
Also known as DEBIAN-CVE-2026-42999, GHSA-2r23-2g6v-2m5f, PYSEC-2026-600, UBUNTU-CVE-2026-42999, USN-8433-1.