Path Traversal in Psi-4ward Psitransfer

CVE-2026-41180

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (37.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-41180: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-41180?
CVE-2026-41180 is a high-severity vulnerability in Psi-4ward Psitransfer, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-04-23.
How severe is CVE-2026-41180?
High severity. CVSS v3 base score is 7.5 out of 10.