Vulnerability · Published Apr 7, 2026 · Assigned by CERT-PL

CVE-2026-33866Authorization Bypass in MLflow AJAX Endpoint

Medium 5.3

In plain English

A medium-severity missing authorization in Mlflow from Mlflow. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.3Medium

Exploit odds (30 days)0.4%top 68.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	mlflow	3.11.0rc0	GHSA-46r5-x6jq-v8g6
PyPI	mlflow	3.11.0rc0	PYSEC-2026-94

Affected products (as reported)

Vendor	Product	Versions
Mlflow	Mlflow	0 – through 3.10.1

Weakness: CWE-862 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

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-become-attack-vectors exploit, technical-description