PYSEC-2026-4112 JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard

Description JupyterLab 4.5.0 enabled copying and pasing cells through the system clipboard. The paste path parses clipboard text as cell JSON and inserts the cells without clearing metadata.trusted, so a payload can declare its own output as trusted. JupyterLab does not sanitize a trusted output...

PYSEC-2026-4058 JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard

Description JupyterLab 4.5.0 enabled copying and pasing cells through the system clipboard. The paste path parses clipboard text as cell JSON and inserts the cells without clearing metadata.trusted, so a payload can declare its own output as trusted. JupyterLab does not sanitize a trusted output...

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

DescriptionJupyterLab 4.5.0 enabled copying and pasing cells through the system clipboard. The paste path parses clipboard text as cell JSON and inserts the cells without clearing metadata.trusted, so a payload can declare its own output as trusted. JupyterLab does not sanitize a trusted output a...

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

DescriptionJupyterLab 4.5.0 enabled copying and pasing cells through the system clipboard. The paste path parses clipboard text as cell JSON and inserts the cells without clearing metadata.trusted, so a payload can declare its own output as trusted. JupyterLab does not sanitize a trusted output a...

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

DescriptionJupyterLab 4.5.0 enabled copying and pasing cells through the system clipboard. The paste path parses clipboard text as cell JSON and inserts the cells without clearing metadata.trusted, so a payload can declare its own output as trusted. JupyterLab does not sanitize a trusted output a...

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

DescriptionJupyterLab 4.5.0 enabled copying and pasing cells through the system clipboard. The paste path parses clipboard text as cell JSON and inserts the cells without clearing metadata.trusted, so a payload can declare its own output as trusted. JupyterLab does not sanitize a trusted output a...

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

Description JupyterLab 4.5.0 enabled copying and pasing cells through the system clipboard. The paste path parses clipboard text as cell JSON and inserts the cells without clearing metadata.trusted, so a payload can declare its own output as trusted. JupyterLab does not sanitize a trusted output...

CVE-2026-102831 JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard

JupyterLab 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...

CVE-2026-102831 JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard

JupyterLab 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...

CVE-2026-102831 JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard

JupyterLab 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...

CVE-2026-102831

The JupyterLab environment is vulnerable to a Cross-site scripting (XSS) attack due to the system clipboard cell-paste path accepting attacker-controlled cell JSON without clearing the metadata.trusted field. When useSystemClipboardForCells is active and pasteCodeCellsWithoutOutput is disabled, a...