XSS in Selfbest

CVE-2025-63416

** 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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-63416: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-63416?
CVE-2025-63416 is a critical-severity vulnerability in Selfbest, classified under Cross-site Scripting. CVSS score: 9.1/10. Published 2025-11-05.
How severe is CVE-2025-63416?
Critical severity. CVSS v3 base score is 9.1 out of 10.