CVE-2026-76404: The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid. in Splunk Splunk MCP Server app
Description
CVE-2026-76404 is a critical vulnerability in the Splunk MCP Server app affecting versions 1.2 and all versions from 1.2 up to but not including 1.2.1. It allows a user with the admin Splunk role to execute arbitrary commands on the underlying operating system due to insecure deserialization of untrusted data in the credential management component.
CVSS v3.1
Score 9.1critical
Affected software
Splunk
Splunk MCP Server app
pkg:github/splunk/mcp-server-appRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Splunk MCP Server app versions >=1.2 and <1.2.1 contain a vulnerability where the application deserializes untrusted data without sufficient validation of the resulting data type. This flaw exists in the credential management component and can be exploited by a user with the admin role to execute arbitrary OS commands. The vulnerability arises from missing input validation during deserialization, leading to potential command injection.
Potential Impact
An attacker with admin privileges in Splunk can leverage this vulnerability to execute arbitrary commands on the underlying operating system, potentially leading to full system compromise. The CVSS v3.1 score is 9.1 (critical), reflecting high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix is available in Splunk MCP Server app version 1.2.1. Users should upgrade to version 1.2.1 or later to remediate this vulnerability. No other mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- cisco
- Date Reserved
- 2026-08-19T12:02:03.632Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a862261acd9273b49a704a5
Added to database: 08/19/2026, 21:38:41 UTC
Last enriched: 09/11/2026, 03:16:52 UTC
Last updated: 10/04/2026, 10:02:29 UTC
Views: 214
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