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Apache SystemDS 3.4.0 Unauthenticated Java Deserialization

Critical
Advisory ID
ZSL-2026-6024
Release Date
18 October 2026
Vendor
The Apache Software Foundation - https://www.apache.org
Affected Version
3.4.0 and 3.5.0-SNAPSHOT
CVE
N/A
Tested On
Microsoft Windows 10, Netty 4.1.96, OpenJDK Temurin 21.0.6
Summary

SystemDS is an open source ML system for the end-to-end data science lifecycle from data integration, cleaning, and feature engineering, over efficient, local and distributed ML model training, to deployment and serving. To this end, it provides a stack of declarative languages with R-like syntax for (1) the different tasks of the data-science lifecycle, and (2) users with different expertise. These high-level scripts are compiled into hybrid execution plans of local, in-memory CPU and GPU operations, as well as distributed operations on Apache Spark.

Description

Apache SystemDS suffer from an unauthenticated Java deserialization vulnerability in its federated worker. The federated worker (started with systemds -w) accepts objects over a Netty channel using ObjectDecoder with no deserialization filtering and no authentication. A remote attacker who can reach the worker port can send a serialized object that is deserialized with no class restriction. This results in unauthenticated remote code execution when a suitable gadget class is present on the federated worker's classpath.

Proof of Concept
Disclosure Timeline
13.08.2026Vulnerability discovered.
18.08.2026Contact with the vendor.
19.08.2026Vendor forwards details to appropriate PMC.
23.09.2026Vendor creates SECURITY.md and rejects this vulnerability.
23.09.2026Replied to the vendor.
18.10.2026Public security advisory released.
Credits
Vulnerability discovered by Gjoko Krstic
References
Changelog
18.10.2026Initial release