CVE-2026-5422: CWE-23 Relative Path Traversal in jupyter jupyter/jupyter
CVE-2026-5422 is a path traversal vulnerability in jupyter-server version 2. 17. 0 caused by improper root directory boundary checks in the _get_os_path() function and insufficient sanitization of path components in to_os_path(). This allows attackers to bypass directory restrictions and access or modify files in sibling directories, potentially exposing sensitive data in shared hosting environments. The vulnerability has a CVSS score of 6. 8 (medium severity). No official patch or remediation guidance is currently available, and no known exploits have been reported in the wild.
AI Analysis
Technical Summary
The vulnerability arises from the _get_os_path() function in jupyter_server/services/contents/fileio.py, which uses a startswith(root) check without appending a trailing path separator, allowing directory traversal via sibling directories with similar name prefixes. Additionally, the to_os_path() function in utils.py does not remove '..' path segments, enabling traversal sequences to bypass the check. This results in unauthorized read/write access to files outside the intended root directory within jupyter-server version 2.17.0.
Potential Impact
Successful exploitation can lead to unauthorized read and write access to files in sibling directories outside the intended root directory. This may expose sensitive data or allow modification of files in shared hosting environments where jupyter-server is deployed. The vulnerability does not affect availability but impacts confidentiality and integrity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider restricting access to jupyter-server instances and carefully control file system permissions to limit potential impact.
CVE-2026-5422: CWE-23 Relative Path Traversal in jupyter jupyter/jupyter
Description
CVE-2026-5422 is a path traversal vulnerability in jupyter-server version 2. 17. 0 caused by improper root directory boundary checks in the _get_os_path() function and insufficient sanitization of path components in to_os_path(). This allows attackers to bypass directory restrictions and access or modify files in sibling directories, potentially exposing sensitive data in shared hosting environments. The vulnerability has a CVSS score of 6. 8 (medium severity). No official patch or remediation guidance is currently available, and no known exploits have been reported in the wild.
CVSS v3.0
Score 6.8medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability arises from the _get_os_path() function in jupyter_server/services/contents/fileio.py, which uses a startswith(root) check without appending a trailing path separator, allowing directory traversal via sibling directories with similar name prefixes. Additionally, the to_os_path() function in utils.py does not remove '..' path segments, enabling traversal sequences to bypass the check. This results in unauthorized read/write access to files outside the intended root directory within jupyter-server version 2.17.0.
Potential Impact
Successful exploitation can lead to unauthorized read and write access to files in sibling directories outside the intended root directory. This may expose sensitive data or allow modification of files in shared hosting environments where jupyter-server is deployed. The vulnerability does not affect availability but impacts confidentiality and integrity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider restricting access to jupyter-server instances and carefully control file system permissions to limit potential impact.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- @huntr_ai
- Date Reserved
- 2026-04-02T12:44:03.302Z
- Cvss Version
- 3.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a1eaa86e29bf47b50bc57e1
Added to database: 6/2/2026, 10:03:50 AM
Last enriched: 6/2/2026, 10:18:52 AM
Last updated: 6/2/2026, 11:57:27 AM
Views: 6
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