GHSA-8mx2-rjh8-q3jq
MEDIUMcopyparty Reflected XSS via Filter Parameter
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
copypartyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Unauthorized reflected Cross-Site-Scripting when accessing the URL for recent uploads with the filter parameter containing JavaScript code.
Details
When accessing the recent uploads page at /?ru, users can filter the results using an input field at the top. This field appends a filter parameter to the URL, which reflects its value directly into a <script> block without proper escaping.
This vulnerability allows for reflected Cross-Site Scripting (XSS) and can be exploited against both authenticated and unauthenticated users, enabling unwanted actions in the victims browser.
PoC
A URL like this will execute alert(1):
https://127.0.0.1:3923/?ru&filter=</script><script>alert(1)</script>
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | copyparty | all versions | 1.18.7 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Copyparty 1.18.6 - Reflected Cross-Site Scripting (XSS)
by Byte Reaper · Aug 3, 2025
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for copyparty. 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 copyparty to 1.18.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8mx2-rjh8-q3jq 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-8mx2-rjh8-q3jq 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-8mx2-rjh8-q3jq. 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-8mx2-rjh8-q3jq in your dependencies?
O3 detects GHSA-8mx2-rjh8-q3jq across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.