CVE-2025-63416: Selfbest

Critical severity, CVSS 9.1. EPSS: 0.4% chance of exploitation in the next 30 days.

** exclusively-hosted-service ** A Stored Cross-Site Scripting (XSS) vulnerability in the chat functionality of the SelfBest platform 2023.3 allows authenticated low-privileged attackers to execute arbitrary JavaScript in the context of other users' sessions. This can be exploited to access administrative data and functions, leading to privilege escalation and full compromise of sensitive user data, as demonstrated by the ability to fetch and exfiltrate the contents of the /admin/users endpoint.

Affected products

• Selfbest Selfbest: version 2023.3 only

Published 2025-11-05. Last modified 2026-06-17.