Authentication Bypass by Primary Weakness Affecting mlflow package, versions <3.16.0-r0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CHAINGUARDLATEST-MLFLOW-19829246
- published16 Sept 2026
- disclosed15 May 2026
Introduced: 15 May 2026
CVE-2026-2652 (opens in a new tab)How to fix?
Upgrade Chainguard mlflow to version 3.16.0-r0 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream mlflow package and not the mlflow package as distributed by Chainguard.
See How to fix? for Chainguard relevant fixed versions and status.
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.