RCE in Code-Projects Simple Chatbox

CVE-2026-6159

A vulnerability has been found in code-projects Simple ChatBox up to 1.0. Affected by this vulnerability is an unknown functionality of the file /chatbox/insert.php of the component Endpoint. Such manipulation of the argument msg leads to cross site scripting. The attack may be performed from remote. The exploit has been disclosed to the public and may be used.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (36.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.5% 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-2026-6159: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-6159?
CVE-2026-6159 is a medium-severity vulnerability in Code-Projects Simple Chatbox, classified under Cross-site Scripting. CVSS score: 4.3/10. Published 2026-04-13.
How severe is CVE-2026-6159?
Medium severity. CVSS v3 base score is 4.3 out of 10.