GHSA-9525-27vj-c8r8 — thorsten/phpmyfaq
HIGHGHSA-9525-27vj-c8r8 is a high-severity (CVSS 7.6) Cross-site Scripting (XSS) vulnerability in thorsten/phpmyfaq. A fix is available for thorsten/phpmyfaq — see the affected versions and patch details below.
phpMyFAQ has stored XSS via Utils::parseUrl() in comment rendering
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-9525-27vj-c8r8.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-9525-27vj-c8r8 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
thorsten/phpmyfaq🐘phpmyfaq/phpmyfaqReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A stored XSS vulnerability in the comment rendering pipeline allows an authenticated user to inject JavaScript that executes for every visitor of an affected FAQ or News page. An attacker with a registered account can steal admin session cookies and take over the application.
Details
Utils::parseUrl() (phpmyfaq/src/phpMyFAQ/Utils.php, line 281) converts URLs in comment text into clickable <a> tags at render time:
$pattern = '/(https?:\/\/[^\s]+)/i';
$replacement = '<a href="$1">$1</a>';
return preg_replace($pattern, $replacement, $string);
The regex [^\s]+ matches " and <, and the URL is inserted into the href attribute with no htmlspecialchars() call. A URL with a literal " closes the attribute early and allows injecting event handlers like onmouseover.
This only reaches the sink when main.enableCommentEditor is enabled. In that path, comment text goes through sanitizeHtmlComment() instead of FILTER_SANITIZE_SPECIAL_CHARS — which encodes " — so the double-quote survives to storage. The comment is then passed through parseUrl() and rendered via {{ comment.comment|raw }} in comment.macros.twig (line 40), which disables Twig auto-escaping.
The same sink exists in the admin comment panel (admin/content/comments.twig, lines 62 and 112), so admins viewing the panel are also affected.
No Content-Security-Policy headers are set anywhere in the app.
PoC
Requirements:
- main.enableCommentEditor = true (set in admin Configuration panel)
- attacker has any registered user account
- one FAQ entry with comments allowed exists
Steps:
-
Log in as a registered user and open a FAQ with comments.
-
Submit the following as the comment text:
https://www.evil.com/"onmouseover="alert(document.cookie)(www. prefix required — parseUrl strips https:// then only re-adds it for www. URLs, which is what triggers the linkification)
-
Any user who views that FAQ page and hovers the link triggers the payload. To hit an admin, wait for them to visit the page or check the admin comments panel at /admin/content/comments.
Resulting HTML in the page:
<a href="https://www.evil.com/"onmouseover="alert(document.cookie)">
...
</a>
The " closes the href attribute; onmouseover becomes a real attribute.
Impact
Stored XSS affecting all visitors of the page, including admins. Session cookie theft leads to full admin account takeover. The payload looks like a normal URL and persists until manually deleted.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | thorsten/phpmyfaq | ≥ 4.1.1&&< 4.1.2 | 4.1.2composer require thorsten/phpmyfaq:^4.1.2 |
| 🐘Packagist | phpmyfaq/phpmyfaq | ≥ 4.1.1&&< 4.1.2 | 4.1.2composer require phpmyfaq/phpmyfaq:^4.1.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for thorsten/phpmyfaq, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update thorsten/phpmyfaq to 4.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9525-27vj-c8r8 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-9525-27vj-c8r8 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-9525-27vj-c8r8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9525-27vj-c8r8 in your dependencies?
O3 Security finds GHSA-9525-27vj-c8r8 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.