GitHub Advisoryadvisory · PyPI

GHSA-75cm-x2w3-8mgf MLflow: unauthenticated access to certain FastAPI routes

HIGH Published 2026-05-15 Modified 2026-05-21 Official page ↗
Aliases
CVE-2026-2652
Ecosystem
PyPI
Packages
mlflow
Severity
High
CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
Weaknesses
CWE-305
Reviewed
2026-05-21

Affected packages

• PyPI mlflow: < 3.11.0 → fixed in 3.11.0

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.

Related

Alias · CVE (1)

  • CVE-2026-2652 A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is… vulnerability

Weakness · CWE (1)

  • CWE-305 Authentication Bypass by Primary Weakness weakness

References