phpMyFAQ has Stored XSS in FAQ Question/Answer via Encode-Decode Bypass of removeAttributes() Sanitization

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2026-46363: 0.19% estimated exploitation activity in the next 30 days; percentile 8.38 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The FAQ creation and update endpoints in phpMyFAQ apply FILTERSANITIZESPECIALCHARS (which HTML-encodes input), then immediately call htmlentitydecode() which reverses the encoding, followed by Filter::removeAttributes() which only strips HTML attributes — not tags. This allows <script, <iframe, <object, and <embed tags to be stored in the database and rendered unescaped via {{ answer|raw }} and {{ question|raw }} in the Twig template, causing JavaScript execution in every visitor's browser. Details Vulnerable code path (FAQ create — FaqController.php): At line 120, the answer content is filtered: Filter::filterVar() calls filterSanitizeString() (Filter.php:135-144) which applies htmlspecialchars(), converting <script to &lt;script&gt;. The regex /\x00|<[^]?/ then finds no literal angle brackets to strip. At lines 150-154, the encoded content is decoded and passed to attribute-only sanitization: htmlentitydecode() converts &lt;script&gt; back to <script, fully reversing the…

Published by the source

6 May 2026, 20:18 UTC

Last modified by the source

9 Jun 2026, 00:00 UTC

Source last checked

26 Oct 2026, 14:48 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-f5p7-2c9q-8896

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# Patch Next advisory brief: CVE-2026-46363

Advisory: phpMyFAQ has Stored XSS in FAQ Question/Answer via Encode-Decode Bypass of removeAttributes() Sanitization
IDs: CVE-2026-46363, GHSA-f5p7-2c9q-8896
Record: https://patchnext.com/advisories/cve-2026-46363 (revision 1, source checked 26 Oct 2026, 14:48 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: phpmyfaq/phpmyfaq 4.1.2; thorsten/phpmyfaq 4.1.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist phpmyfaq/phpmyfaq: affected <= 4.1.1; fixed in 4.1.2
- Packagist thorsten/phpmyfaq: affected <= 4.1.1; fixed in 4.1.2

## Suggested inspection (read-only)
- Packagist phpmyfaq/phpmyfaq: check the installed version with your package manager.
- Packagist thorsten/phpmyfaq: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on phpmyfaq/phpmyfaq, thorsten/phpmyfaq.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-f5p7-2c9q-8896 (GitHub-reviewed advisory GHSA-f5p7-2c9q-8896 lists affected ranges: Packagist phpmyfaq/phpmyfaq >=0 =0 <=4.1.1)

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