CVE-2026-76395: Remote Code Execution (RCE) through Deserialization of Untrusted Data in the Model Loading REST API in Splunk AI Toolkit

What it is

In Splunk AI Toolkit versions below 6.0.0, a user who holds the "power" Splunk role could execute arbitrary code on the Splunk server by loading a model file containing crafted sparse matrix data. The deserialization of untrusted data is possible because a model codec in Splunk AI Toolkit deserializes sparse matrix data without guarding against embedded pickle content. For more information see Troubleshoot the Splunk Machine Learning Toolkit (https://help.splunk.com/en/splunk-cloud-platform/apply-machine-learning/machine-learning-toolkit-user-guide/5.5.0/troubleshooting-mltk/troubleshoot-the-splunk-machine-learning-toolkit) in the Splunk documentation.

Workarounds

Turn off or remove the Splunk AI Toolkit app. For more information see [Manage app and add-on objects](https://help.splunk.com/en/splunk-enterprise/administer/admin-manual/10.2/meet-splunk-apps/manage-app-and-add-on-objects) in the Splunk documentation. Note: turning off Splunk AI Toolkit turns off AI Toolkit Search Processing Language (SPL) commands and model operations. Splunk App for Data Science and Deep Learning and custom search commands that depend on AI Toolkit models or APIs might stop functioning. Unrelated Splunk custom search commands are not affected. For more information see [Troubleshoot the Splunk Machine Learning Toolkit](https://help.splunk.com/en/splunk-cloud-platform/apply-machine-learning/use-ai-toolkit/5.5.0/troubleshooting-mltk/troubleshoot-the-splunk-machine-learning-toolkit) and [DSDL install/version dependencies](https://help.splunk.com/en/splunk-enterprise/apply-machine-learning/splunk-app-for-data-science-and-deep-learning/5.1/install-and-configure-the-splunk-app-for-data-science-and-deep-learning/install-or-upgrade-the-splunk-app-for-data-science-and-deep-learning) in the Splunk documentation.