CVE-2026-42998
Description
A flaw was found in OpenStack Keystone. The application credential authentication plugin fails to verify if the user provided in an authentication request matches the owner of the application credential. This allows a remote attacker to authenticate with their own credentials while impersonating another user, gaining unauthorized access to project-scoped resources and potentially evading audits. The attacker can read the victim's credentials and act as the victim within shared projects.
Statement
This MODERATE impersonation vulnerability in Keystone's application credential plugin allows authenticated users to obtain tokens attributed to other users. Exploitation requires high complexity (valid app credentials and shared project context). Impact is limited to the intersection of attacker's app credential roles and victim's actual project roles. Affects versions before 29.0.2.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.9 | 8.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Unchanged | N/A |
| Confidentiality | Low | High | N/A |
| Integrity Impact | Low | High | N/A |
| Availability Impact | None | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
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