Cyber Resilience

CVE-2026-43001

Access Control in Openstack Keystone 14.0.0 – 27.0.2

Public PoCAccess Control
Published
01 May 2026
Modified
15 July 2026
Patch / advisory
CVSS Score v3.1 7.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
EPSS Score 0.0046 38th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2026-43001 is a high-severity Incorrect Authorization (CWE-863) vulnerability in Openstack Keystone. Its CVSS base score is 7.9 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 38th 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.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-43001 is a vulnerability affecting OpenStack Keystone versions 13 through 29. The flaw occurs in the POST /v3/credentials endpoint, which does not validate that the caller-supplied project_id for an EC2-type credential matches the project associated with the authenticating application credential. This issue, published on 2026-05-01, is categorized under CWE-863 (Incorrect Authorization) and carries a CVSS v3.1 base score of 7.9 (AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L).

An attacker with an unrestricted application credential scoped to project A can exploit this vulnerability over the network. By creating an EC2-type credential specifying a project_id for project B, the attacker can then perform a /v3/ec2tokens exchange to obtain a Keystone token scoped to project B. This token retains the original app_cred_id, enabling cross-project lateral movement within the footprint of the credential owner's roles, potentially granting high confidentiality and integrity impacts across scope boundaries.

Advisories and patches addressing this vulnerability are detailed in the OpenStack Keystone bug tracker at https://bugs.launchpad.net/keystone/+bug/2149775 and the associated code review patch at https://review.opendev.org/c/openstack/keystone/+/985804.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An issue was discovered in OpenStack Keystone before 29.0.2. POST /v3/credentials did not validate that the caller-supplied project_id for an EC2-type credential matched the project of the authenticating application credential. This allowed an attacker holding an unrestricted application credential for…

more

project A to create an EC2 credential targeting project B; a subsequent /v3/ec2tokens exchange would then issue a Keystone token scoped to project B while still carrying the original app_cred_id, enabling cross-project lateral movement within the credential owner's role footprint.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1548.002 Bypass User Account Control Privilege Escalation
Adversaries may bypass UAC mechanisms to elevate process privileges on system.
T1548.003 Sudo and Sudo Caching Privilege Escalation
Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-44394Same product: Openstack Keystone
CVE-2026-42998Same product: Openstack Keystone
CVE-2026-33551Same product: Openstack Keystone
CVE-2026-42999Same product: Openstack Keystone
CVE-2026-43000Same product: Openstack Keystone
CVE-2026-50589Same vendor: Openstack
CVE-2024-29156Same vendor: Openstack
CVE-2026-50221Same vendor: Openstack
CVE-2026-34881Same vendor: Openstack
CVE-2026-48681Same vendor: Openstack

Affected Assets

openstack
keystone
14.0.0 — 27.0.2 · 28.0.0 — 28.0.2 · 29.0.0 — 29.0.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V2.2.2
  • V4.2.3
  • V12.3.2

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.

SI-10 requires validity checks on supplied inputs, directly stopping acceptance of internally inconsistent complex data.

Least-privilege assignments shrink the set of authorizations that must be checked correctly, limiting exposure to flawed checks.

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.

PR.AA-05 mostly match
prevents

Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect authorization checks.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require consistency validation for complex inputs.

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.

finds

Security testing can detect consistency flaws but does not prevent them at design time.

prevents

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.

prevents

Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.

prevents

Secure development lifecycle requires input validation and consistency checks that directly address CWE-1288.

prevents

Application security requirements include validation of complex inputs and cross-field consistency.

prevents

Secure architecture principles encourage robust input handling but do not specifically mandate consistency validation.

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 (2 rules)
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
  • V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863
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 (1 rule)
  • V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863

References