{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:jupyter:jupyterlab:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "4.0.0"
              },
              {
                "fixed": "4.5.7"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "66351c7d2f350756ca0436abc66e6c9848e0c6af"
            },
            {
              "fixed": "f51404192bf6d0ff79187c884f21e1f91b928146"
            }
          ],
          "repo": "https://github.com/jupyterlab/jupyterlab",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-37w4-hwhx-4rc4"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-602",
      "CWE-88"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42266.json"
  },
  "details": "JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager (allowed_extensions_uris) is not correctly enforced by JupyterLab. The PyPI Extension Manager was not contained to packages listed on the default PyPI index. This vulnerability is fixed in 4.5.7.",
  "id": "CVE-2026-42266",
  "modified": "2026-07-16T03:31:16.868478142Z",
  "published": "2026-05-13T15:08:49.846Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7"
    },
    {
      "type": "WEB",
      "url": "https://jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html"
    },
    {
      "type": "WEB",
      "url": "https://jupyterlab.readthedocs.io/en/latest/user/extensions.html#extension-manager-implementations"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42266.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/security/cve/CVE-2026-42266"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42266.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42266"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2477072"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "JupyterLab has an Extension Manager API/GUI Policy Discrepancy allowing 3rd party (malicious) extensions install via POST request."
}