XSS in Thorsten Phpmyfaq

CVE-2026-56736

phpMyFAQ is an open source FAQ web application. A stored cross-site scripting (XSS) vulnerability in versions prior to 4.2.0-alpha allows any unauthenticated user (or low-privileged registered user) to inject arbitrary JavaScript that executes in an administrator's browser when they review or edit a user-submitted FAQ entry. This leads to admin account takeover via session theft. The vulnerability exists because `html_entity_decode()` converts HTML entities into executable HTML after `strip_tags()` has already passed them through, and the admin template renders the content with Twig's `|raw` filter without any output sanitization. Version 4.2.0-alpha fixes the issue.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-56736?
CVE-2026-56736 is a high-severity vulnerability in Thorsten Phpmyfaq, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2026-09-24.
How severe is CVE-2026-56736?
High severity. CVSS v3 base score is 8.2 out of 10.