jupyterlab: Extension Manager API/GUI Policy Discrepancy allowing 3rd party (malicious) extensions install via POST request._CVE-2026-42266

{
    "lastseen": "",
    "description": "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.",
    "published": "2026-05-13T15:08:49.846Z",
    "modified": "2026-05-13T15:08:49.846Z",
    "type": "cve",
    "title": "jupyterlab: Extension Manager API/GUI Policy Discrepancy allowing 3rd party (malicious) extensions install via POST request.",
    "source": "GitHub_M",
    "references": "https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4",
    "id": "CVE-2026-42266",
    "bulletinFamily": "",
    "cwe": [
        "CWE-88",
        "CWE-602"
    ],
    "cvelist": null,
    "sourceData": "jupyterlab jupyterlab >= 4.0.0, < 4.5.7",
    "sourceHref": "",
    "cvss": {
        "score": 8.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "jupyterlab",
    "version": ">= 4.0.0, < 4.5.7",
    "vendor": "jupyterlab",
    "ai_description": "Extension Manager API/GUI Policy Discrepancy allowing 3rd party (malicious) extensions install via POST request",
    "ai_severity": "High",
    "ai_vendor": "Project Jupyter",
    "ai_product": "JupyterLab",
    "ai_version": "4.0.0-4.5.6",
    "ai_score": 8.8
}