phpMyFAQ has a SVG Sanitizer Entity Decoding Depth Limit Bypass Leading to Stored XSS

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-2026-46360: 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 SvgSanitizer::decodeAllEntities() method limits recursive entity decoding to 5 iterations. By wrapping each character of javascript in an href attribute value with 5 levels of & encoding around numeric HTML entities (e.g., j for j), an attacker can bypass both isSafe() detection and sanitize() removal. The uploaded SVG is served from the application origin with image/svg+xml content type, and the browser's XML parser fully decodes the remaining &#NNN; entities, resulting in a clickable javascript: link that executes arbitrary JavaScript. Details Root cause: decodeAllEntities() at phpmyfaq/src/phpMyFAQ/Helper/SvgSanitizer.php:223-249 limits entity decoding to maxIterations=5. Each iteration: (1) decodes &#NNN; numeric entities, (2) decodes &#xHH; hex entities, (3) calls htmlentitydecode() which resolves one level of & → &. With 5 levels of & wrapping, all 5 iterations are consumed unwinding the & nesting, leaving the final &#NNN;…

Published by the source

6 May 2026, 20:18 UTC

Last modified by the source

9 Jun 2026, 00:03 UTC

Source last checked

26 Oct 2026, 14:48 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-whqh-9pq5-c7r3

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# Patch Next advisory brief: CVE-2026-46360

Advisory: phpMyFAQ has a SVG Sanitizer Entity Decoding Depth Limit Bypass Leading to Stored XSS
IDs: CVE-2026-46360, GHSA-whqh-9pq5-c7r3
Record: https://patchnext.com/advisories/cve-2026-46360 (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-whqh-9pq5-c7r3 (GitHub-reviewed advisory GHSA-whqh-9pq5-c7r3 lists affected ranges: Packagist phpmyfaq/phpmyfaq >=0 =0 <=4.1.1)

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