Vulnerability details

CVE-2026-2652

mlflow mlflow/mlflow

Authentication Bypass in mlflow/mlflow

CVSS 3.0

8.6High

Official 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.

CVSS scores

Score	Version	Source	Vector
8.6High	3.0	CVEProject cvelistV5 (CNA) (@huntr_ai)	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L`

Affected products

Vendor	Product	Versions	Source
mlflow	mlflow/mlflow	v < 3.10.0	CVEProject cvelistV5 (CNA)

References and advisories

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Details

Published: 2026-05-15
Last updated: 2026-05-15
State: Published
Assigner (CNA): @huntr_ai

Exploit prediction (EPSS)

20.78%

Probability of exploitation in 30 days

97.5%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: Yes
Exploitation: Proof of concept
Technical impact: Partial

Weaknesses (CWE)

CWE-305
Authentication Bypass by Primary Weakness