Authorization Bypass in MLflow Affects Model Artifact Access
CVE-2026-33866

5.3MEDIUM

Key Information:

Vendor

Mlflow

Status
Mlflow
Vendor
CVE Published:
7 April 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-33866?

MLflow, a popular open-source platform for managing the machine learning lifecycle, is susceptible to an authorization bypass issue. This vulnerability arises from inadequate access-control validation on the AJAX endpoint used for downloading saved model artifacts. As a result, an unauthorized user can directly access and query this endpoint, allowing them to retrieve model artifacts they should not have permissions to access. This issue is present in MLflow versions up to 3.10.1, underscoring the need for users to review their configurations and apply available patches to secure their systems.

Affected Version(s)

Mlflow 0 <= 3.10.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-33866 - Proof of Concept

References

https://github.com/mlflow/mlflow/pull/21708
patch
https://cert.pl/en/posts/2026/04/CVE-2026-33865/
third-party-advisory
https://afine.com/blogs/attacking-mlflow-how-ml-artifacts...
exploittechnical-description

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Sławomir Zakrzewski (AFINE)
.