{
  "cveId": "CVE-2026-35397",
  "url": "https://patchblox.com/security/cve/CVE-2026-35397",
  "summary": "CVE-2026-35397 is fixed in jupyter-server on 1 platform by DEBIAN-CVE-2026-35397 (version 2.20.0-1), released May 5, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "jupyter-server: Jupyter Server is the backend for Jupyter web applications",
  "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 \u0022test\u0022, the API permits access to a sibling directory named \u0022testtest\u0022 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 \u0022user1\u0022 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.",
  "published": "2026-05-05T20:16:38Z",
  "severity": "high",
  "cvss": 8.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00622,
  "epssPercentile": 0.50054,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "jupyter-server",
      "release": "Debian 14",
      "fixedVersion": "2.20.0-1",
      "fix": "DEBIAN-CVE-2026-35397",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-35397",
      "released": "2026-05-05T20:16:38Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}