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 (https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/1.2/configure-the-splunk-mcp-server) and Managing custom tools in Splunk MCP Server (https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/1.2/managing-custom-tools-in-splunk-mcp-server) in the Splunk documentation.

Scores

EPSS (exploitation in 30 days)

0.17% · top 93% of all CVEs (5 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.

Weakness

• CWE-918: The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. (opens in a new tab)All about CWE-918 and its CVEs

Affected products

• Splunk · Splunk MCP Server

  • affected 1.2 – < 1.2.1

What to do

Solution: Upgrade Splunk MCP Server to version 1.2.1 or higher.

Workaround: Turn off or remove the Splunk MCP Server 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.

References (1)

• https://advisory.splunk.com/advisories/SVD-2026-1004 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-76286](https://trackcve.app/badge/CVE-2026-76286.svg)](https://trackcve.app/cve/CVE-2026-76286)

Record last updated 8 Oct 2026, 18:00 UTC.