CVE-2026-76286 Server-Side Request Forgery (SSRF) through Custom API Tools in Splunk MCP Server
Attackers can capture authentication tokens via SSRF in custom API tools, allowing unauthorized data access and actions as the victim user.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-76286?
CVE-2026-76286 is a medium-severity server-side request forgery vulnerability in Splunk MCP Server, published on 7 Oct 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-918
Which versions are affected by CVE-2026-76286?
How do I fix CVE-2026-76286?
No fix has been published for CVE-2026-76286 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-76286 being exploited?
There is no known exploitation of CVE-2026-76286 in the wild and no public exploit code.
Sources
Also known as GHSA-mgwr-9j5x-6w4x.