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 names begin with the same prefix as the root_dir. For example, with a root_dir named "test", the API permits access to a sibling directory named "testtest" through a crafted request to the /api/contents endpoint using encoded path components. An attacker can read, write, and delete files in affected sibling directories. Multi-tenant deployments using predictable naming schemes are particularly at risk, as a user with a directory named "user1" could access directories for user10 through user19 and beyond. A user who can choose a single-character folder name could gain access to a significant number of sibling directories.
Version 2.18.0 contains a fix. As a workaround, ensure folder names do not share a common prefix with any sibling directory.
Metrics
Affected Vendors & Products
References
History
Wed, 06 May 2026 16:15:00 +0000
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ssvc
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Tue, 05 May 2026 21:45:00 +0000
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Jupyter
Jupyter jupyter Server |
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Jupyter
Jupyter jupyter Server |
Tue, 05 May 2026 20:00:00 +0000
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| Description | 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 names begin with the same prefix as the root_dir. For example, with a root_dir named "test", the API permits access to a sibling directory named "testtest" through a crafted request to the /api/contents endpoint using encoded path components. An attacker can read, write, and delete files in affected sibling directories. Multi-tenant deployments using predictable naming schemes are particularly at risk, as a user with a directory named "user1" could access directories for user10 through user19 and beyond. A user who can choose a single-character folder name could gain access to a significant number of sibling directories. Version 2.18.0 contains a fix. As a workaround, ensure folder names do not share a common prefix with any sibling directory. | |
| Title | jupyter-server path traversal allows access to sibling directories sharing root_dir name prefix | |
| Weaknesses | CWE-22 | |
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-05-05T19:37:33.810Z
Updated: 2026-05-07T03:55:44.058Z
Reserved: 2026-04-02T17:03:42.074Z
Link: CVE-2026-35397
Updated: 2026-05-06T15:48:56.918Z
Status : Received
Published: 2026-05-05T20:16:38.223
Modified: 2026-05-06T16:16:07.750
Link: CVE-2026-35397
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