Path Traversal in Jupyter Jupyter_server

CVE-2026-35397

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, a path traversal vulnerability in the REST API allows an authenticated user to escape the configured root_dir and access sibling directories whose…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.000 (13.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-35397?
CVE-2026-35397 is a high-severity vulnerability in Jupyter Jupyter_server, classified under Path Traversal. CVSS score: 8.8/10. Published 2026-05-05.
How severe is CVE-2026-35397?
High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2026-35397 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.