CVE-2026-20205: splunk splunk mcp server

Vulnerability summary

CVE-2026-20205 is a high (CVSS 7.2) vulnerability in splunk splunk mcp server. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 18.9% of scored vulnerabilities.

Timeline

1. 15-04-2026
   PublishedVulnerability first disclosed.
2. 15-04-2026
   Last modifiedVulnerability information updated.

Description

In Splunk MCP Server app versions below 1.0.3 , a user who holds a role with access to the Splunk `_internal` index or possesses the high-privilege capability `mcp_tool_admin` could view users session and authorization tokens in clear text.<br><br>The vulnerability would require either local access to the log files or administrative access to internal indexes, which by default only the admin role receives. <br><br>Review roles and capabilities on your instance and restrict internal index access to administrator-level roles. See [Define roles on the Splunk platform with capabilities](https://docs.splunk.com/Documentation/Splunk/latest/Security/Rolesandcapabilities) and [Connecting to MCP Server and Admin settings](https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/connecting-to-mcp-server-and-admin-settings) in the Splunk documentation for more information.

• CWE-532Insertion of Sensitive Information into Log FileThe product writes sensitive information to a log file.