jupyterlab: Command linker attributes in HTML enable one-click command execution from untrusted content_CVE-2026-42557

{
    "lastseen": "",
    "description": "jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.",
    "published": "2026-05-13T15:06:14.222Z",
    "modified": "2026-05-13T15:06:14.222Z",
    "type": "cve",
    "title": "jupyterlab: Command linker attributes in HTML enable one-click command execution from untrusted content",
    "source": "GitHub_M",
    "references": "https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-mqcg-5x36-vfcg",
    "id": "CVE-2026-42557",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "jupyterlab jupyterlab < 4.5.7\njupyter notebook >= 7.0.0, < 7.5.6",
    "sourceHref": "",
    "cvss": {
        "score": 8.6,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "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": "< 4.5.7",
    "vendor": "jupyterlab",
    "ai_description": "Arbitrary code execution via deceptive button in HTML cell output",
    "ai_severity": "High",
    "ai_vendor": "Project Jupyter",
    "ai_product": "JupyterLab",
    "ai_version": "< 4.5.7",
    "ai_score": 8.6
}