JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-102831
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-29 19:17:25 UTC
Updated2026-09-29 19:17:25 UTC
DescriptionJupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From JupyterLab 4.5.0 until 4.5.11 and 4.6.4, from Notebook 7.5.0 until 7.6.3, and from JupyterLite Core 0.7.0 until 0.8.4, the system clipboard cell-paste path accepts attacker-controlled cell JSON without clearing metadata.trusted. When useSystemClipboardForCells is active and pasteCodeCellsWithoutOutput is disabled, a pasted code cell can mark HTML output as trusted, bypass output sanitization, and execute script in the authenticated JupyterLab origin without executing the cell. Markdown and raw cells are not affected because their output is sanitized. This issue is fixed in JupyterLab 4.5.11 and 4.6.4, Notebook 7.6.3, and JupyterLite Core 0.8.4.

Risk And Classification

Primary CVSS: v3.1 8.1 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Problem Types: CWE-79 | CWE-345 | CWE-79 CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | CWE-345 CWE-345: Insufficient Verification of Data Authenticity

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary8.1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
3.1CNADECLARED8.1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Jupyterlab Jupyterlab affected >= 4.5.0, < 4.5.11 Not specified
CNA Jupyterlab Jupyterlab affected >= 4.6.0, < 4.6.4 Not specified
CNA Jupyterlab Notebook affected >= 7.5.0, < 7.6.3 Not specified
CNA Jupyterlab Jupyterlite-core affected >= 0.7.0, < 0.8.4 Not specified

References

ReferenceSourceLinkTags
github.com/jupyterlab/jupyterlab/commit/7f9f29e29e0c83fb17b0f11da57d06b3... [email protected] github.com
github.com/jupyterlab/jupyterlab/commit/cf6e89a8d315c4134cefa50c220bca29... [email protected] github.com
github.com/jupyterlab/jupyterlab/commit/1a10a7da5ff655849b21581c2633b464... [email protected] github.com
github.com/jupyterlab/jupyterlab/releases/tag/v4.5.11 [email protected] github.com
github.com/jupyterlab/jupyterlab/security/advisories/GHSA-6966-vjj6-99xv [email protected] github.com
github.com/jupyterlab/jupyterlab/releases/tag/v4.6.4 [email protected] github.com
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