What is CVE-2025-53858?

CVE-2025-53858 is a medium-severity vulnerability in Neojapan Inc. Chatluck, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-10-16.

How severe is CVE-2025-53858?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Neojapan Inc. Chatluck

CVE-2025-53858

ChatLuck contains a cross-site scripting vulnerability in Chat Rooms. If exploited, an arbitrary script may be executed on the web browser of the user who is accessing the product.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (12.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

Neojapan Inc. Chatluck — versions V6.6 R2.0 and earlier

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

vultures@jpcert.or.jp
vultures@jpcert.or.jp

Frequently asked questions

What is CVE-2025-53858?: CVE-2025-53858 is a medium-severity vulnerability in Neojapan Inc. Chatluck, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-10-16.
How severe is CVE-2025-53858?: Medium severity. CVSS v3 base score is 5.4 out of 10.