MLflow: unauthenticated access to certain FastAPI routesGHSA-75cm-x2w3-8mgf
HIGHFix: mlflow/mlflow@bb62e77GHSA-75cm-x2w3-8mgf is a high-severity (CVSS 8.6) CWE-305 vulnerability in mlflow. EPSS puts its 30-day exploitation probability at 20.8% (98th percentile). A fix is available for mlflow — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-75cm-x2w3-8mgf.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
mlflowReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | mlflow | all versions | 3.11.0pip install --upgrade 'mlflow==3.11.0' |
Affected Products
mlflowlfprojectsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mlflow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mlflow to 3.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-75cm-x2w3-8mgf is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
How to detect GHSA-75cm-x2w3-8mgf
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-75cm-x2w3-8mgf -u https://target- Template
- MLflow < 3.10.0 - Authentication Bypass on FastAPI Routes
- Severity
- high
- Impact
- An unauthenticated attacker can bypass authentication to access job management APIs and inject arbitrary trace data, potentially leading to data integrity compromise and unauthorized job execution.
- Remediation
- Upgrade MLflow to version 3.10.0 or later.
Template by ProjectDiscovery nuclei-templates (DhiyaneshDk), MIT licensed. View the full template. Scan only systems you are authorised to test.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This Important authentication bypass vulnerability in mlflow does not affect Red Hat products as the vulnerable code is not present.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for GHSA-75cm-x2w3-8mgf (CC BY 4.0)
Frequently Asked Questions
Is GHSA-75cm-x2w3-8mgf in your dependencies?
Find it across PyPI, including transitive dependencies.