cve-2026-2652

HIGH vulncheck_kev
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.

Timeline
Published
2026-08-07 00:00 UTC
Last Modified
2026-08-07
CVSS Details

CVSS details not available.

Affected Products

No product information available.

References

No references available.

Linked Vulnerabilities

No linked vulnerabilities found.

{
  "cvss": 0.0,
  "datePublished": "2026-08-07T00:00:00Z",
  "dateUpdated": "2026-08-07T00:00:00Z",
  "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.",
  "dueDate": "",
  "id": "CVE-2026-2652",
  "kev_catalogs": [
    "vulncheck"
  ],
  "knownRansomwareCampaignUse": "Unknown",
  "product": "MLflow",
  "requiredAction": "Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.",
  "severity": "HIGH",
  "source": "vulncheck_kev",
  "title": "lfprojects MLflow Authentication Bypass by Primary Weakness",
  "vendor": "lfprojects"
}
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