CVE-2026-41180 is a high-severity (CVSS 7.5) vulnerability in psitransfer. O3 Security confirms whether CVE-2026-41180 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
PsiTransfer: Upload PATCH path traversal can create `config.<NODE_ENV>.js` and lead to code execution on restart
Real-World Exposure
psitransferReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
PsiTransfer is an open source, self-hosted file sharing solution. Prior to version 2.4.3, the upload PATCH flow under /files/:uploadId validates the mounted request path using the still-encoded req.path, but the downstream tus handler later writes using the decoded req.params.uploadId. In deployments that use a supported custom PSITRANSFER_UPLOAD_DIR whose basename prefixes a startup-loaded JavaScript path, such as conf, an unauthenticated attacker can create config.<NODE_ENV>.js in the application root. The attacker-controlled file is then executed on the next process restart. Version 2.4.3 contains a patch.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | psitransfer | all versions | 2.4.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for psitransfer. 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 psitransfer to 2.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41180 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 CVE-2026-41180 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 CVE-2026-41180. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-41180 in your dependencies?
O3 detects CVE-2026-41180 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.