phpMyFAQ has Stored XSS in Admin FAQ Editor via HTML Entity Bypass in Frontend FAQ Submission

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

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.

[ Fixes ]Fixes and patches

• thorsten/phpmyfaq 4.2.0-alphaFixed version · GitHub Advisories · composer package thorsten/phpmyfaq: upgrade to 4.2.0-alpha or later (affected < 4.2.0-alpha)
• phpmyfaq/phpmyfaq 4.2.0-alphaFixed version · GitHub Advisories · composer package phpmyfaq/phpmyfaq: upgrade to 4.2.0-alpha or later (affected < 4.2.0-alpha)

[ Packages ]Affected open-source packages

• thorsten/phpmyfaq composerAffected < 4.2.0-alpha · fixed in 4.2.0-alpha · GHSA-pgwp-vc7q-cvj3
• phpmyfaq/phpmyfaq composerAffected < 4.2.0-alpha · fixed in 4.2.0-alpha · GHSA-pgwp-vc7q-cvj3

[ References ]References

• github.com/thorsten/phpMyFAQ/security/advisories/GHSA-pgwp-vc7q-cvj3