{"id":"CVE-2026-40171","revision":"637edd38638e41cfb7564707b9876cc9","records":[{"revision":"637edd38638e41cfb7564707b9876cc9","observedAt":"2026-10-27T10:09:56.341+00:00","statement":{"source":"nvd","id":"CVE-2026-40171","aliases":[],"title":"In Jupyter Notebook versions 7.0.0 through 7.5.5, JupyterLab versions 4.5.6 and earlier, and the corresponding @jupyter-notebook/help-extension and @jupyterlab/help-extension packages before 7.5.6 and 4.5.7, a stored cross-site scripting is…","description":"In Jupyter Notebook versions 7.0.0 through 7.5.5, JupyterLab versions 4.5.6 and earlier, and the corresponding @jupyter-notebook/help-extension and @jupyterlab/help-extension packages before 7.5.6 and 4.5.7, a stored cross-site scripting issue in the help command linker can be chained with attacker-controlled notebook content to steal authentication tokens with a single click.\n\nAn attacker can craft a malicious notebook file containing elements that appear indistinguishable from legitimate controls and trigger execution when a user interacts with them. Successful exploitation allows theft of the user's authentication token and complete takeover of the Jupyter session through the REST API, including reading files, creating or modifying files, accessing kernels to execute arbitrary code, and creating terminals for shell access. This issue has been fixed in Notebook 7.5.6, JupyterLab 4.5.7, @jupyter-notebook/help-extension 7.5.6, and @jupyterlab/help-extension 4.5.7. As a workaround, disable the affected help extensions or set allowCommandLinker to false in the sanitizer configuration.","state":0,"publishedAt":"2026-05-06T20:16:31.857+00:00","modifiedAt":"2026-10-26T19:10:00.163+00:00","affected":[],"metrics":[{"system":"CVSS 4.0 · security-advisories@github.com · Secondary","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","score":8.4,"severity":"HIGH"}],"references":["https://github.com/jupyter/notebook/security/advisories/GHSA-rch3-82jr-f9w9"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-40171","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Awaiting Analysis","weaknesses":["CWE-79"],"productCriteria":[],"sourceDates":{"published":"2026-05-06T20:16:31.857","lastModified":"2026-10-26T19:10:00.163"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-40171","identifiers":["CVE-2026-40171"]},"retained":false,"historicalAffected":[]}],"coverage":[]}