CVE-2026-85593: phpMyFAQ before 4.1.8 Stored XSS via html_entity_decode

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-04 · updated 2026-09-14
Weakness: CWE-79

Description

phpMyFAQ versions before 4.1.8 contain a stored cross-site scripting vulnerability in FaqHelper::convertOldInternalLinks() that calls html_entity_decode() on sanitized FAQ content, reversing entity-encoding protection. Authenticated users with FAQ editing privileges can inject JavaScript payloads that execute in the browsers of all users viewing the affected FAQ pages.

Affected products

thorsten phpMyFAQ: before 4.1.8 — fixed in 4.1.8

How to fix

Upgrade to a fixed version: thorsten phpMyFAQ 4.1.8. Check the vendor advisory for mitigations.

References

https://github.com/thorsten/phpMyFAQ/security/advisories/GHSA-x6qj-5jhf-xgpm
https://www.vulncheck.com/advisories/phpmyfaq-before-4.1.8-stored-xss-via-html-entity-decode

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