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)

Published 2025-10-16 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.002 (13.9th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

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

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

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.