CVE-2026-33866
Authorization Bypass in MLflow AJAX Endpoint
Description
MLflow is vulnerable to an authorization bypass affecting the AJAX endpoint used to download saved model artifacts. Due to missing access‑control validation, a user without permissions to a given experiment can directly query this endpoint and retrieve model artifacts they are not authorized to access. This issue affects MLflow version through 3.10.1
INFO
Published Date :
April 7, 2026, 1:16 p.m.
Last Modified :
April 20, 2026, 6:45 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update MLflow to a patched version.
- Verify access controls on artifact download endpoints.
Public PoC/Exploit Available at Github
CVE-2026-33866 has a 4 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-33866.
| URL | Resource |
|---|---|
| https://afine.com/blogs/attacking-mlflow-how-ml-artifacts-become-attack-vectors | Exploit Third Party Advisory |
| https://cert.pl/en/posts/2026/04/CVE-2026-33865/ | Third Party Advisory |
| https://github.com/mlflow/mlflow/pull/21708 | Issue Tracking Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-33866 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-33866
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
None
None
CVEs, conference materials, research.
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-33866 vulnerability anywhere in the article.
-
cert.pl
Vulnerabilities in Mlflow software
Vulnerabilities in Mlflow software CVE ID CVE-2026-33865 Publication date 07 April 2026 Vendor Mlflow Product Mlflow Vulnerable versions All through 3.10.1 Vulnerability type (CWE) Improper Neutraliza ... Read more
The following table lists the changes that have been made to the
CVE-2026-33866 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Added CPE Configuration OR *cpe:2.3:a:lfprojects:mlflow:*:*:*:*:*:*:*:* versions up to (including) 3.10.1 Added Reference Type CERT.PL: https://afine.com/blogs/attacking-mlflow-how-ml-artifacts-become-attack-vectors Types: Exploit, Third Party Advisory Added Reference Type CERT.PL: https://cert.pl/en/posts/2026/04/CVE-2026-33865/ Types: Third Party Advisory Added Reference Type CERT.PL: https://github.com/mlflow/mlflow/pull/21708 Types: Issue Tracking, Patch -
CVE Modified by [email protected]
Apr. 09, 2026
Action Type Old Value New Value Added Reference https://afine.com/blogs/attacking-mlflow-how-ml-artifacts-become-attack-vectors -
New CVE Received by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added Description MLflow is vulnerable to an authorization bypass affecting the AJAX endpoint used to download saved model artifacts. Due to missing access‑control validation, a user without permissions to a given experiment can directly query this endpoint and retrieve model artifacts they are not authorized to access. This issue affects MLflow version through 3.10.1 Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-862 Added Reference https://cert.pl/en/posts/2026/04/CVE-2026-33865/ Added Reference https://github.com/mlflow/mlflow/pull/21708