Splunk is widely deployed enterprise software; an admin-role RCE can lead to host compromise and broad operational impact.
CVE-2026-76404
Splunk MCP Server (<1.2.1) insecure deserialization allows admin OS command execution
Is CVE-2026-76404 being exploited?
Not confirmed. CVE-2026-76404 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.56% probability of exploitation in the next 30 days.
How severe is CVE-2026-76404?
CVE-2026-76404 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-76404?
Yes. A fix has been recorded for CVE-2026-76404. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-76404 affect?
CVE-2026-76404 affects Splunk MCP Server app <1.2.1, Splunk Enterprise instances with MCP Server app installed. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-76404?
Upgrade MCP Server app to >=1.2.1, restrict/rotate admin accounts, isolate affected hosts
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated Splunk admin can execute arbitrary OS commands, enabling host takeover, data exfiltration, and lateral movement.
Immediate action required
- affected>= 1.2 and < 1.2.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.