CVE-2026-35397

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.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5789-5fc7-67v3	Exploit Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:43038
https://access.redhat.com/errata/RHSA-2026:60520
https://access.redhat.com/security/cve/CVE-2026-35397
https://bugzilla.redhat.com/show_bug.cgi?id=2466858
https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5789-5fc7-67v3	Exploit Vendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35397.json

Configurations

Configuration 1 (hide)

cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-05-05 20:16

Updated : 2026-08-28 16:17

NVD link : CVE-2026-35397

Mitre link : CVE-2026-35397

CVE.ORG link : CVE-2026-35397

JSON object : View

Products Affected

jupyter

jupyter_server

CWE

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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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. \n\nVersion 2.18.0 contains a fix. As a workaround, ensure folder names do not share a common prefix with any sibling directory."}, {"lang": "es", "value": "Jupyter Server es el backend para las aplicaciones web de Jupyter. En las versiones 2.17.0 y anteriores, una vulnerabilidad de salto de ruta en la API REST permite a un usuario autenticado escapar del 'root_dir' configurado y acceder a directorios hermanos cuyos nombres comienzan con el mismo prefijo que el 'root_dir'. Por ejemplo, con un 'root_dir' llamado test , la API permite el acceso a un directorio hermano llamado testtest a trav\u00e9s de una solicitud manipulada al endpoint '/api/contents' utilizando componentes de ruta codificados. Un atacante puede leer, escribir y eliminar archivos en los directorios hermanos afectados. Las implementaciones multi-inquilino que utilizan esquemas de nombres predecibles est\u00e1n particularmente en riesgo, ya que un usuario con un directorio llamado user1 podr\u00eda acceder a los directorios de user10 a user19 y m\u00e1s all\u00e1. Un usuario que puede elegir un nombre de carpeta de un solo car\u00e1cter podr\u00eda obtener acceso a un n\u00famero significativo de directorios hermanos.\n\nLa versi\u00f3n 2.18.0 contiene una correcci\u00f3n. Como soluci\u00f3n alternativa, aseg\u00farese de que los nombres de las carpetas no compartan un prefijo com\u00fan con ning\u00fan directorio hermano."}], "lastModified": "2026-08-28T16:17:45.870", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E0B6C703-7E28-4F23-9878-E157975C32A4", "versionEndExcluding": "2.18.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}