Remote Code Execution (RCE) through Deserialization of Untrusted Data in Splunk MCP Server app

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-76404
StatePUBLISHED
Assignercisco
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-19 22:17:27 UTC
Updated2026-08-20 13:01:40 UTC
DescriptionIn 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.

Risk And Classification

Primary CVSS: v3.1 9.1 CRITICAL from [email protected]

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Problem Types: CWE-502 | CWE-502 The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
3.1CNACVSS9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Splunk Splunk MCP Server App affected 1.2 1.2.1 custom Not specified

References

ReferenceSourceLinkTags
advisory.splunk.com/advisories/SVD-2026-0808 [email protected] advisory.splunk.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Kuniyoshi Noguchi (KuniNogu) (en)

Additional Advisory Data

Solutions

CNA: Upgrade each affected Splunk app or add-on to the applicable fixed version listed in Product Status.

Workarounds

CNA: Turn off or remove the Splunk MCP Server app. For more information see [Manage app and add-on objects](https://help.splunk.com/en/splunk-enterprise/administer/admin-manual/10.2/meet-splunk-apps/manage-app-and-add-on-objects) in the Splunk documentation.

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