A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (`--app-name basic-auth`) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on `/gateway/` routes, leaving other routes such as the Job API (`/ajax-api/3.0/jobs/*`) and the OpenTelemetry trace ingestion API (`/v1/traces`) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the `_find_fastapi_validator()` function fails to handle non-`/gateway/` paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
History

Fri, 15 May 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 15 May 2026 05:00:00 +0000

Type Values Removed Values Added
First Time appeared Mlflow
Mlflow mlflow/mlflow
Vendors & Products Mlflow
Mlflow mlflow/mlflow

Fri, 15 May 2026 03:00:00 +0000

Type Values Removed Values Added
Description A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (`--app-name basic-auth`) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on `/gateway/` routes, leaving other routes such as the Job API (`/ajax-api/3.0/jobs/*`) and the OpenTelemetry trace ingestion API (`/v1/traces`) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the `_find_fastapi_validator()` function fails to handle non-`/gateway/` paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
Title Authentication Bypass in mlflow/mlflow
Weaknesses CWE-305
References
Metrics cvssV3_0

{'score': 8.6, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: @huntr_ai

Published:

Updated: 2026-05-15T13:22:21.060Z

Reserved: 2026-02-18T02:53:33.607Z

Link: CVE-2026-2652

cve-icon Vulnrichment

Updated: 2026-05-15T13:22:08.836Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-15T03:16:23.127

Modified: 2026-05-15T14:56:18.253

Link: CVE-2026-2652

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-15T04:45:36Z