A stored XSS vulnerability in Elastic Kibana, rated at 8.7 (High) severity, allows authenticated attackers to execute arbitrary scripts in the context of other users.

This is a stored cross-site scripting (XSS) vulnerability caused by improper neutralization of input during web page generation. An attacker with low-level privileges can trigger this flaw by uploading a malicious file to the case management feature, which subsequently executes the script when accessed by other users.

Successful exploitation allows an attacker to execute arbitrary JavaScript within the browser session of a victim, potentially leading to unauthorized actions, session hijacking, or sensitive data theft. Given the 8.7 CVSS score, this represents a significant risk to the integrity and confidentiality of the Kibana environment, particularly if administrative users interact with malicious case files.

Immediate Action: Upgrade Kibana to versions 8.18.8, 8.19.5, 9.0.8, 9.1.5, or later as specified in the official Elastic security advisory.

Proactive Monitoring: Review Kibana audit logs for unusual file upload activity or anomalous interactions within the case management module.

Compensating Controls: Implement a strict Content Security Policy (CSP) to restrict script execution sources and ensure that users with file upload permissions are strictly managed and monitored.

Public Exploit Available: Unknown

This vulnerability presents a clear risk of cross-site scripting that could compromise user sessions and data within the Kibana interface. Administrators must prioritize the application of the provided security updates to the affected versions of Kibana to eliminate the risk of arbitrary script execution.