CVE-2026-42999
Published: 28 May 2026
Summary
CVE-2026-42999 is a medium-severity Incorrect Authorization (CWE-863) vulnerability in Openstack Keystone. Its CVSS base score is 6.0 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 24.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-33241
Vulnerability details
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…
more
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).
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The RBAC bypass in the public Keystone API directly enables exploitation of a public-facing service (T1190) to achieve unauthorized privilege escalation (T1068) via attribute injection.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Applying decisions to each request prior to enforcement mitigates incorrect authorization by enforcing consistent policy evaluation.
Mandating policy-based enforcement reduces the chance of incorrect authorization logic being used.
Periodic review and update of procedures reduces incorrect authorization implementations over time.
Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.
Defining permitted attribute values and auditing modifications reduces the chance of incorrect authorization outcomes due to tampered or missing labels.
The authorization process and usage restrictions help prevent incorrect authorization for remote access types.
Establishing configuration and connection requirements helps ensure correct rather than incorrect authorization for wireless access.
Establishing connection authorization processes for mobile devices helps ensure authorization decisions are correctly implemented rather than incorrect.