PYSEC-2026-68
Vulnerability from pysec - Published: 2026-05-05 20:16 - Updated: 2026-05-20 09:19Jupyter 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.
| Name | purl | jupyter-server | pkg:pypi/jupyter-server |
|---|
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "jupyter-server",
"purl": "pkg:pypi/jupyter-server"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.18.0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.0.0",
"0.0.1",
"0.0.2",
"0.0.3",
"0.0.4",
"0.0.5",
"0.1.0",
"0.1.1",
"0.2.0",
"0.2.1",
"0.3.0",
"1.0.0",
"1.0.0rc0",
"1.0.0rc1",
"1.0.0rc10",
"1.0.0rc11",
"1.0.0rc12",
"1.0.0rc13",
"1.0.0rc14",
"1.0.0rc15",
"1.0.0rc16",
"1.0.0rc2",
"1.0.0rc3",
"1.0.0rc4",
"1.0.0rc5",
"1.0.0rc6",
"1.0.0rc7",
"1.0.0rc8",
"1.0.0rc9",
"1.0.1",
"1.0.10",
"1.0.11",
"1.0.2",
"1.0.3",
"1.0.4",
"1.0.5",
"1.0.6",
"1.0.7",
"1.0.8",
"1.0.9",
"1.1.0",
"1.1.1",
"1.1.2",
"1.1.3",
"1.1.4",
"1.10.0",
"1.10.1",
"1.10.2",
"1.11.0",
"1.11.1",
"1.11.2",
"1.12.0",
"1.12.1",
"1.13.0",
"1.13.1",
"1.13.2",
"1.13.3",
"1.13.4",
"1.13.5",
"1.15.0",
"1.15.1",
"1.15.2",
"1.15.3",
"1.15.4",
"1.15.5",
"1.15.6",
"1.16.0",
"1.17.0",
"1.17.1",
"1.18.0",
"1.18.1",
"1.19.0",
"1.19.1",
"1.2.0",
"1.2.1",
"1.2.2",
"1.2.3",
"1.21.0",
"1.23.0",
"1.23.1",
"1.23.2",
"1.23.3",
"1.23.4",
"1.23.5",
"1.23.6",
"1.24.0",
"1.3.0",
"1.4.0",
"1.4.1",
"1.5.0",
"1.5.1",
"1.6.0",
"1.6.1",
"1.6.2",
"1.6.3",
"1.6.4",
"1.7.0",
"1.7.0a1",
"1.7.0a2",
"1.8.0",
"1.9.0",
"2.0.0",
"2.0.0a0",
"2.0.0a1",
"2.0.0a2",
"2.0.0b0",
"2.0.0b1",
"2.0.0rc0",
"2.0.0rc1",
"2.0.0rc2",
"2.0.0rc3",
"2.0.0rc4",
"2.0.0rc5",
"2.0.0rc6",
"2.0.0rc7",
"2.0.0rc8",
"2.0.1",
"2.0.2",
"2.0.3",
"2.0.4",
"2.0.5",
"2.0.6",
"2.0.7",
"2.1.0",
"2.10.0",
"2.10.1",
"2.11.0",
"2.11.1",
"2.11.2",
"2.12.0",
"2.12.1",
"2.12.2",
"2.12.3",
"2.12.4",
"2.12.5",
"2.13.0",
"2.14.0",
"2.14.1",
"2.14.2",
"2.15.0",
"2.16.0",
"2.17.0",
"2.2.0",
"2.2.1",
"2.3.0",
"2.4.0",
"2.5.0",
"2.6.0",
"2.7.0",
"2.7.1",
"2.7.2",
"2.7.3",
"2.8.0",
"2.9.0",
"2.9.1"
]
}
],
"aliases": [
"CVE-2026-35397",
"GHSA-5789-5fc7-67v3"
],
"details": "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. \n\nVersion 2.18.0 contains a fix. As a workaround, ensure folder names do not share a common prefix with any sibling directory.",
"id": "PYSEC-2026-68",
"modified": "2026-05-20T09:19:02.924837Z",
"published": "2026-05-05T20:16:38.223Z",
"references": [
{
"type": "EVIDENCE",
"url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5789-5fc7-67v3"
}
],
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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