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GHSA-75cm-x2w3-8mgf BIT-mlflow-2026-2652 CVE-2026-2652 PYSEC-2026-2221

MLflow: unauthenticated access to certain FastAPI routes

High PyPI
Severity
8.6 / 10
High · CVSS 3.0
Exploit chance (EPSS)
20.78%
Chance of exploitation in the next 30 days. Higher than 97.54% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-305 Authentication Bypass by Primary Weakness
Fix
3.11.0
Upgrade mlflow to this version or later

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.

Affected versions

PyPI

PackageVulnerableFixed in
mlflow
< 3.11.0
3.11.0
mlflow
< 3.10.0
3.10.0

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

mlflow PyPI → 3.11.0

pip
pip install --upgrade "mlflow>=3.11.0"
poetry
poetry add "mlflow>=3.11.0"
uv
uv add "mlflow>=3.11.0"

Severity breakdown

CVSS 3.0 8.6

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
Low

Weakness

CWE-305: Authentication Bypass by Primary Weakness

The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-7gwp-5pfp-969j
MLflow: Unauthenticated full-read SSRF in webhook delivery: _validate_webhook_url bypassed via unvalidated HTTP redirects (and DNS rebinding)
Critical Known exploited Also affects mlflow
GHSA-26p8-2jq9-3vq9
MLflow vulnerable to remote code execution on unauthenticated servers via third-party scorer deserialization importing caller-placed artifact modules
Critical Also affects mlflow
GHSA-j7qq-vr8c-xvw3
MLflow CrewAI autologging records LLM provider API keys in logged trace spans
Medium Also affects mlflow
GHSA-m65p-9j7q-6w33
MLflow vulnerable to arbitrary file read on unauthenticated servers via prompt model version source
High Also affects mlflow
GHSA-2wqp-q3c6-ccj5
MLflow: SSRF on unauthenticated MLflow servers via third-party scorer kwargs in the scorer invoke, register, and GenAI evaluate endpoints
Medium Also affects mlflow
GHSA-wqmh-qccw-pqwf
MLflow FileStore trace IDs allow path traversal and arbitrary file writes
High Also affects mlflow
GHSA-gqvg-gmmx-x4hm
MLFLOW_ALLOW_PICKLE_DESERIALIZATION=False safety control bypassed by mlflow.statsmodels flavor — RCE via crafted model artifact
High Also affects mlflow
GHSA-h7x2-h6g9-p789
MLflow AI Gateway permits SSRF through an unvalidated api_base
High Also affects mlflow
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