CVE-2026-2652

Authentication Bypass in mlflow/mlflow

Published May 15, 2026 CVSS 3.0 · 8.6 High EPSS 20.8% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-75cm-x2w3-8mgf MLflow: unauthenticated access to certain FastAPI routes
History
Type Values Removed Values Added
First Time appeared Lfprojects
Lfprojects mlflow
CPEs cpe:2.3:a:lfprojects:mlflow:*:*:*:*:*:*:*:*
Vendors & Products Lfprojects
Lfprojects mlflow
Type Values Removed Values Added
Metrics ssvc

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

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
@huntr_ai
Published
Updated
May 15, 2026, 1:22 PM
Reserved
Feb 18, 2026, 2:53 AM
Status
Analyzed
Published
May 15, 2026, 3:16 AM
Modified
Nov 11, 2026, 8:10 PM