CVE-2026-42999: Openstack Keystone

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

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 products

• Openstack Keystone: from 14.0.0, before 27.0.2 (fixed in 27.0.2); from 28.0.0, before 28.0.2 (fixed in 28.0.2); from 29.0.0, before 29.0.2 (fixed in 29.0.2)

Published 2026-05-28. Last modified 2026-07-23.