Quick answers
- Is CVE-2026-76404 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-76404 being exploited in the wild.
- How severe is CVE-2026-76404?
- Critical severity, with a CVSS score of 9.1, published 19 August 2026.
- Which products and versions are affected?
- Splunk MCP Server app below 1.2.1.
- Is there a fix for CVE-2026-76404?
- A patch was published on 2026-08-19: Fix version 1.2.1 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-76404 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-76404?
- Check whether you run Splunk MCP Server app or Splunk Model Context Protocol Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
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