CVE-2026-64849 MLflow Server-Side Request Forgery
Unauthenticated attackers can exploit Server-Side Request Forgery in MLflow webhooks to access internal services and cloud metadata via redirect bypasses.
- Exploited in the wild
- Since 19 Aug 2026
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64849?
CVE-2026-64849 is a critical server-side request forgery vulnerability in Lfprojects Mlflow, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
MLflow is an open source AI engineering platform for agents, large language models, and machine learning models. Starting in 3.3.0 and prior to 3.15.0, the unauthenticated POST /api/2.0/mlflow/webhooks/{id}/test endpoint calls _validate_webhook_url() in mlflow/utils/validation.py only for the original URL while mlflow/webhooks/delivery.py follows redirects and re-resolves the hostname without pinning the validated address, allowing attackers to reach internal or cloud metadata services and receive response_status and response_body. This issue is fixed in version 3.15.0.
Weakness: CWE-918
Which versions are affected by CVE-2026-64849?
4 open source packages ship an affected version, including mlflow. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mlflow Bitnami | From 3.3.0 | 3.15.0 |
mlflow PyPI | All versions | 3.15.0 |
mlflow PyPI | From 3.3.0 | 3.15.0 |
mlflow PyPI | From 3.3.0 | 3.15.0 |
Products include Lfprojects Mlflow.
How do I fix CVE-2026-64849?
Upgrade mlflow to 3.15.0 or later. US federal agencies must fix it by 2 Sep 2026.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-64849 being exploited?
Yes. Attackers have exploited CVE-2026-64849 in the wild since at least 19 Aug 2026.
Public exploit code: 1 Nuclei template and 5 proofs of concept on GitHub.
Other vulnerabilities in Lfprojects Mlflow
- CVE-2025-15379 Command Injection in mlflow/mlflow
- CVE-2024-0520 Remote Code Execution due to Full Controlled File Write in mlflow/mlflow
- CVE-2023-6977 Path Traversal: '\..\filename'
- CVE-2023-6709 Improper Neutralization of Special Elements Used in a Template Engine in mlflow/mlflow
- CVE-2023-6015 MLflow Arbitrary File Upload
Sources
Also known as BIT-mlflow-2026-64849, GHSA-7gwp-5pfp-969j, MINI-8g3x-hmjq-4q5r, PYSEC-2026-3687.