phpMyFAQ Stored Cross-site Scripting at File AttachmentsGHSA-hm8r-95g3-5hj9
MEDIUMGHSA-hm8r-95g3-5hj9 is a medium-severity (CVSS 4.3) Cross-site Scripting (XSS) vulnerability in phpmyfaq/phpmyfaq. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for phpmyfaq/phpmyfaq — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-hm8r-95g3-5hj9.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
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 | 3.2.6composer require phpmyfaq/phpmyfaq:^3.2.6 |
Affected Products
phpmyfaqphpmyfaqResearch 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-hm8r-95g3-5hj9 in your dependencies?
Find it across Packagist, including transitive dependencies.