Path traversal in Jupyter Server - CVE-2026-35397
Published: September 3, 2026
Vulnerability identifier: #VU146865
CSH Severity: Low
CVSS v4: 7.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-35397
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose sensitive information and modify data outside the intended directory scope.
The vulnerability exists due to path traversal in jupyter-server REST API when handling crafted path inputs relative to the root_dir. A remote user can send a specially crafted request to disclose sensitive information and modify data outside the intended directory scope.
Access is limited to a subset of directories that are siblings of the configured root_dir.
Affected software
Jupyter Server
How to mitigate CVE-2026-35397
Install security update from vendor's website.
Jupyter Server - update to 2.18.0