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CVE-2026-2652highobserved exploitationCWE-305

Authentication Bypass in mlflow/mlflow

63Vexday Risk Score

Patch now. It exploitation observed by VulnCheck and has a working public exploit.

ssvc Actcvss 8.6epss 19%
from disclosure to weapon
Published on NVDMay 15
VulnCheck+84d
exploitation probability
19%top 3% of all CVEs
observed exploitation
yesVulnCheck
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.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
Affected products
mlflow · mlflow/mlflow