CVE-2026-76286
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
In Splunk MCP Server versions below 1.2.1, the server could send the Splunk platform authentication token of a user who runs a custom 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 with a role containing the mcp_tool_execute capability to run a custom API tool configured by another user.
Risk Assessment
An attacker could capture the authentication token and gain unauthorized access to data and perform actions on behalf of the victim, potentially leading to confidentiality and integrity breaches.
Recommendation
Upgrade Splunk MCP Server to version 1.2.1 or later. Limit trust in custom API tools and monitor their configuration.
Other vulnerabilities in Splunk MCP Server
See all- CVE-2026-76404Critical
In Splunk MCP Server app versions below 1.2.1, a user who holds the "admin" Splunk role could execute arbitrary commands on the underlying operating system. The vulnerability is possible because of missing input validation in the app's credential management component, which deserializes stored data without checking whether the content is of the expected type.
- CVE-2025-20381Medium
In Splunk MCP Server app versions below 0.2.4, a user with access to the 'run_splunk_query' Model Context Protocol (MCP) tool could bypass the SPL command allowlist controls in MCP by embedding SPL commands as sub-searches, leading to unauthorized actions beyond the intended MCP restrictions.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS