JupyterPYSEC-2026-2532
Jupyter Server vulnerable to Path Traversal via incorrect root directory boundary check in _get_os_path()
Medium6.8CVE-2026-5422 · Published Jul 13, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| jupyter-server PyPI | < 2.18.2 | 2.18.2 |
Details and references
A path traversal vulnerability exists in jupyter-server version 2.17.0 due to an incorrect root directory boundary check in the _get_os_path() function within jupyter_server/services/contents/fileio.py. The check uses startswith(root) without appending a trailing path separator, allowing sibling directories with names starting with the same prefix as root_dir to bypass the check. Additionally, the to_os_path() function in utils.py does not strip ".." from path parts, enabling traversal sequences to bypass the vulnerable check. This vulnerability can lead to unauthorized read/write access to files in sibling directories, potentially exposing sensitive data in shared hosting environments.
- CVSS 3.0
- CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
- Severity from
- the CVSS score
- Also known as
- CVE-2026-5422, GHSA-gf7q-q4j7-hp7c
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