CVE-2026-76346: Stored Cross-Site Scripting (XSS) through Splunk Web Dashboard Sparkline Format Options in Splunk Enterprise

In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, a user who holds the "power" Splunk role could store a malicious script in dashboard sparkline format options and execute unauthorized JavaScript in the browser of another user who views the dashboard. If the other user holds the "admin" Splunk role, the script could access all relevant data available through Splunk Web and perform actions with that user's permissions. The vulnerability is possible because Splunk Web does not limit the permitted dashboard visualization options to safe presentation settings and does not escape tooltip values before rendering them. The vulnerability requires the attacker to phish the affected user by tricking them into initiating a request within their browser. The user who holds the "power" Splunk role should not be able to exploit the vulnerability at will. For more information see About configuring role-based user access (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.2/manage-splunk-platform-users-and-roles/about-configuring-role-based-user-access) in the Splunk documentation.