CVE-2026-93860
Description
A flaw was found in OpenStack Mistral. The maintenance API endpoint is missing an authorization check, allowing any authenticated user to activate global maintenance mode on the Mistral service. When an attacker triggers maintenance mode, all write operations (workflow execution creation, environment creation, and similar API calls) are blocked across all tenant projects on the affected Mistral deployment. This results in a denial of service for all tenants until an administrator or the attacker restores normal operation.
Statement
Red Hat product impact analysis pending. Component mapping is required to determine which Red Hat OpenStack Platform (RHOSP) releases ship an affected version of OpenStack Mistral (versions older than 20.1.1 and exactly 21.0.0, 22.0.0, or 23.0.0). The vulnerability requires the Mistral API to be network-accessible and Keystone authentication to be enabled; deployments where the Mistral API is not exposed or where Mistral is not included are not affected.
Mitigation
No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability.
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 | 6.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat CVSS v3 Score Explanation
Network-accessible API, no special conditions, any valid auth token sufficient; no data disclosed or corrupted; entire Mistral service write-path is blocked for all tenants while maintenance mode is active
Acknowledgements
Upstream acknowledges Chen YuXiang (Institute of Computing Technology, Chinese Academy of Sciences) as the original reporter.
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