Vulnerability · Published Aug 19, 2026 · Assigned by cisco

CVE-2026-76404Remote Code Execution (RCE) through Deserialization of Untrusted Data in Splunk MCP Server app

Critical 9.1

In plain English

A critical-severity unsafe deserialization in Splunk MCP Server app from Splunk. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities).

Severity (CVSS 3.1)9.1Critical

Exploit odds (30 days)0.7%top 44.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

In 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.

Affected products (as reported)

Vendor	Product	Versions
Splunk	Splunk MCP Server app	1.2 – before 1.2.1

Weakness: CWE-502 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

References

https://advisory.splunk.com/advisories/SVD-2026-0808