CVE-2026-43001
Description
A flaw was found in OpenStack Keystone. An attacker holding an unrestricted application credential could exploit a vulnerability in the POST /v3/credentials endpoint where the caller-supplied project_id for an EC2-type credential was not validated against the project of the authenticating application credential. This allows the attacker to create an EC2 credential targeting a different project. Subsequently, a /v3/ec2tokens exchange would issue a Keystone token scoped to the targeted project, enabling unauthorized cross-project access and lateral movement within the credential owner's role footprint.
Statement
This flaw in OpenStack Keystone allows an attacker with an unrestricted application credential to bypass project isolation. By exploiting improper validation during EC2 credential creation, an attacker can gain unauthorized access and move laterally between projects within a Red Hat OpenStack Platform deployment, compromising multi-tenant security. If the roles from the original project the attacker holds a credential are compatible with the roles in the project the attacker is targeting, the attacker can perform the same actions granted permission from the initial project in the targeted project. Depending on the level of privileges the attacker has that means a high impact for confidentiality, availability and integrity.
Mitigation
To reduce exposure, ensure that OpenStack application credentials are created with the most restrictive scope possible, limiting their permissions to only what is essential for their intended function. If EC2 credentials are not actively used within your OpenStack deployment, consider disabling the EC2 credential API endpoint in Keystone to prevent unauthorized creation of cross-project EC2 credentials. Refer to the OpenStack Keystone administration guide for detailed instructions on managing application credential scopes and disabling API endpoints. Any changes to Keystone configuration may require a service restart to take effect.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8 | 8 | 8 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | High | High |
| Privileges Required | High | High | High |
| User Interaction | None | None | None |
| Scope | Changed | Changed | Changed |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
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