Junglewise Threat Intelligence

CVE-2026-76404: Splunk MCP Server app remote code execution through deserialization

CVE-2026-76404 · Severity: critical · CVSS 9.1 · Published 2026-08-19

Vendors: Splunk.

Executive brief

The Splunk MCP Server app is a credential management component used in Splunk deployments to integrate with external systems. Versions below 1.2.1 allow admin-level users to execute arbitrary commands on the underlying operating system due to improper deserialization of stored credentials. An attacker with admin privileges could gain complete control of the host system running Splunk.

Technical details

This vulnerability is a deserialization flaw (CWE-502) in the Splunk MCP Server app's credential management component. The application deserializes stored credential data without validating that the content matches the expected data type, allowing an authenticated admin user to inject malicious serialized objects. An admin-role user can craft malicious credentials that, when deserialized, execute arbitrary system commands with the privileges of the Splunk process. Exploitation requires admin-level authentication within Splunk. The vulnerability has been patched in version 1.2.1 and later.

Affected products

  • Splunk MCP Server app below 1.2.1

Timeline

  • 2026-08-19: disclosed
  • 2026-08-19: patched: Fix version 1.2.1 released

References