Security Vulnerability in Splunk MCP Server - September/October 2026
Advisory ID: SVD-2026-1004
Published: 2026-10-07
Highest CVSSv3.1 Score: 5.3, Medium
Last Updated: 2026-10-07
Description
In Splunk MCP Server versions below 1.2.1, a user that holds a role with the mcp_tool_admin capability could configure a custom Application Programming Interface (API) tool to send requests to an attacker-controlled Uniform Resource Locator (URL). Only a user that holds a role with the mcp_tool_execute capability could run that tool. Exploitation requires a user that holds a role with the mcp_tool_execute capability.
Solutions
Upgrade Splunk MCP Server to version 1.2.1 or higher.
Product Status
| Product | Base Version | Component | Affected Version | Fix Version |
|---|---|---|---|---|
| Splunk MCP Server | 1.2 | REST API | Below 1.2.1 | 1.2.1 |
Vulnerabilities
| CVE | Summary | CWE | Severity | Score |
|---|---|---|---|---|
| CVE-2026-76286 | Server-Side Request Forgery (SSRF) through Custom API Tools in Splunk MCP Server | CWE-918 | Medium | 5.3 |
CVE Details
CVE-2026-76286: Server-Side Request Forgery (SSRF) through Custom API Tools in Splunk MCP Server
Description
In Splunk MCP Server versions below 1.2.1, Splunk MCP Server could send the Splunk platform authentication token of a user who runs a custom Application Programming Interface (API) tool to the URL configured for that tool. If another user controls that URL, they could capture the token and use it to access data and perform actions as the user who ran the tool. Successful exploitation requires a user who holds a role that contains the mcp_tool_execute capability to run a custom API tool configured by another user. For more information see Configure the Splunk MCP Server and Managing custom tools in Splunk MCP Server in the Splunk documentation.
Bug ID: VULN-83777
CWE: CWE-918
CVSSv3.1 Score: 5.3, Medium
CVSSv3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:L/A:L
Mitigations and Workarounds
Turn off or remove the Splunk MCP Server app. For more information see Manage app and add-on objects in the Splunk documentation.
Acknowledgments: Kuniyoshi Noguchi (KuniNogu)