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
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.
Why this VPI (explainable, experimental)
VPI breakdown
| Impact | 81.00 |
| Exploitation signal(No additional exploitation signal) | ×1.00 |
| VPI | 81.00 |
VPI formula vpi-v1
| Source | CVSS Version | Base Score | Severity | Vector String | Assessment Date |
|---|---|---|---|---|---|
| OSV3rd | 3.1 | 6.8 | MEDIUM | CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N | 07/10/2026 |
| NVDNIST | 3.1 | 8.1 |
| CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| 06/04/2026 |
| NVDNIST | 3.0 | 6.8 | MEDIUM | CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N | 06/02/2026 |