GHSA-hm8r-95g3-5hj9
MEDIUMphpMyFAQ Stored Cross-site Scripting at File Attachments
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.
Blast Radius
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
An attacker with admin privileges can upload an attachment containing JS code without extension and the application will render it as HTML which allows for XSS attacks.
Details
When attachments are uploaded without an extension, the application renders it as HTML by default. Therefore allowing attackers to upload .html files containing javascript code to perform XSS attacks. The direct file path to the uploaded attachment is also easily obtainable as it is made up of substrings of the file's MD5 hashes.
PoC
-
Admin users can upload attachments containing XSS payloads in files without extensions to bypass the .html extension check.
-
Since the path of the uploaded file is built entirely on the file’s MD5 hash and the attachment directory, it is possible for an attacker to know the direct path of the uploaded file.
E.g file MD5 hash: 38fff51cb7248a06d6142c6bdf846831
URL will be: http://127.0.0.1/phpmyfaq/attachments/38fff/51cb7/248a0/6d6142c6bdf846831
- /attachments
- /38fff (first 5 chars of MD5 hash)
- /51cb7 (next 5 chars of MD5 hash)
- /248a0 (next 5 chars of MD5 hash)
- /6d6142c6bdf846831 (remaining chars of MD5 hash)
3. Even though the attachment was uploaded without a file extension, it is still rendered as .html, hence triggering the XSS payload.
Impact
This allows an attacker to execute arbitrary client side JavaScript within the context of another user's phpMyFAQ session.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | phpmyfaq/phpmyfaq | ≥ 3.2.5&&< 3.2.6 | 3.2.6 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phpmyfaq/phpmyfaq. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update phpmyfaq/phpmyfaq to 3.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hm8r-95g3-5hj9 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 pinpoints whether GHSA-hm8r-95g3-5hj9 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-hm8r-95g3-5hj9. 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-hm8r-95g3-5hj9 in your dependencies?
O3 detects GHSA-hm8r-95g3-5hj9 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.