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

CVE-2026-33865Stored XSS via unsafe YAML parsing in MLflow

Medium 5.1

In plain English

A medium-severity cross-site scripting in Mlflow from Mlflow. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.1Medium

Exploit odds (30 days)0.2%top 86.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

MLflow is vulnerable to Stored Cross-Site Scripting (XSS) caused by unsafe parsing of YAML-based MLmodel artifacts in its web interface. An authenticated attacker can upload a malicious MLmodel file containing a payload that executes when another user views the artifact in the UI. This allows actions such as session hijacking or performing operations on behalf of the victim. This issue affects MLflow version through 3.10.1

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	mlflow	3.11.1	GHSA-fh64-r2vc-xvhr
PyPI	mlflow	3.11.0rc0	PYSEC-2026-93

Affected products (as reported)

Vendor	Product	Versions
Mlflow	Mlflow	0 – through 3.10.1

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N

References

https://github.com/mlflow/mlflow/pull/21435 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