JupyterLab: Cross-site scripting (XSS) in JupyterLab via crafted language package (jupyterlab.json)

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0026, the 17th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 14:09 UTC First seen by agentprime
2. 31 Oct 2026, 14:09 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-3jqq-pw4j-pqcj
• OSV: GHSA-3jqq-pw4j-pqcj
• github.com/jupyterlab/jupyterlab/security/advisories/GHSA-3jqq-pw4j-pqcj
• nvd.nist.gov/vuln/detail/CVE-2026-102830
• github.com/jupyterlab/jupyterlab/commit/985a3223cd77fd4f991cd90066342a90711d70f6
• github.com/jupyterlab/jupyterlab/commit/de324ae91346c713c4f5e5485f97b6e914e0f774
• github.com/jupyterlab/jupyterlab/commit/f9de43dc565a1118120d466117f877a189a4ce90
• github.com/jupyterlab/jupyterlab
• github.com/jupyterlab/jupyterlab/releases/tag/v4.5.11
• github.com/jupyterlab/jupyterlab/releases/tag/v4.6.4

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.