Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:LSummary
CVE-2026-43000 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 25th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-33242
Vulnerability Data
An issue was discovered in OpenStack Keystone before 29.0.2. When combined with an application credential impersonation vulnerability, an attacker with the member role on a project can escalate to admin by chaining unrestricted application credentials with Keystone trusts. The impersonated…
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token carries the victim's identity, which passes the trustor validation check. Keystone then validates the delegated roles against the victim's actual role assignments in the database, not the roles on the requesting token. This allows the attacker to create a trust delegating the victim's admin role to themselves. The trust persists independently, and additional trusts and application credentials can be created to maintain access. All actions are logged under the victim's identity.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 13 hardening rules · 7 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
AC-3 directly requires correct enforcement of authorization decisions on every access request, structurally preventing incorrect checks.
AC-24 ensures access-control decisions are made and applied consistently, reducing the chance of an incorrect authorization result.
A reference monitor that is always invoked and tamper-proof forces every authorization decision through a verified, correct path.
Least privilege directly requires that only the minimal necessary privileges are assigned to each actor.
Account management defines and authorizes the exact privileges granted to each account or role.
Separation of duties constrains which privilege combinations may be assigned to any actor.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Directly enforces least-privilege policy definition, management, and review that prevents incorrect privilege assignments.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
The access-rights control governs the entire lifecycle of privilege assignment, directly eliminating incorrect assignments.
Privileged-access-rights control explicitly requires least-privilege assignment and ongoing validation, directly mitigating CWE-266.
Requiring consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.
Segregation of duties reduces blast radius of any single incorrect privilege but does not prevent the assignment itself.
Restricting privileged utility programs limits exposure from over-privileged accounts but does not address how privileges are assigned.
By tying access rights to identity, device, location and classification, the control reduces the likelihood that an authorization decision will be based on an incorrect or bypassed policy.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (3 rules)
- V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
- V-248551 A sticky bit must be set on all OL 8 public directories to prevent unauthorized and unintended information transferred via shared system resources. prevents CWE-266
- V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863
Oracle Linux 9 (1 rule)
- V-271779 OL 9 must be configured so that a sticky bit must be set on all public directories. prevents CWE-266
RHEL 7 (1 rule)
- V-204430 The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation. prevents CWE-863
RHEL 8 (2 rules)
- V-230243 A sticky bit must be set on all RHEL 8 public directories to prevent unauthorized and unintended information transferred via shared system resources. prevents CWE-266
- V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863
RHEL 9 (1 rule)
- V-257929 A sticky bit must be set on all RHEL 9 public directories. prevents CWE-266
Ubuntu 22.04 (2 rules)
- V-260513 Ubuntu 22.04 LTS must set a sticky bit on all public directories to prevent unauthorized and unintended information transferred via shared system resources. prevents CWE-266
- V-260559 Ubuntu 22.04 LTS must ensure only users who need access to security functions are part of sudo group. prevents CWE-266
Ubuntu 24.04 (2 rules)
- V-270748 Ubuntu 24.04 LTS must ensure only users who need access to security functions are part of sudo group. prevents CWE-266
- V-270750 Ubuntu 24.04 LTS must set a sticky bit on all public directories to prevent unauthorized and unintended information transferred via shared system resources. prevents CWE-266