8.1
HIGH CVSS 3.1
CVE-2026-102831
JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard
Description

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 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.

INFO

Published Date :

Sept. 29, 2026, 7:17 p.m.

Last Modified :

Sept. 29, 2026, 7:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-102831 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Update JupyterLab, Notebook, and JupyterLite Core to patched versions to fix clipboard security issues.
  • Update JupyterLab to version 4.5.11 or later.
  • Update Notebook to version 7.6.3 or later.
  • Update JupyterLite Core to version 0.8.4 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-102831 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-102831 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-102831 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-102831 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 29, 2026

    Action Type Old Value New Value
    Added Description 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 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
    Added CWE CWE-79
    Added CWE CWE-345
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/102xxx/CVE-2026-102831.json">CVE-2026-102831</a>
    Added Reference https://github.com/jupyterlab/jupyterlab/commit/1a10a7da5ff655849b21581c2633b46483ae0be9
    Added Reference https://github.com/jupyterlab/jupyterlab/commit/7f9f29e29e0c83fb17b0f11da57d06b3c6a40d96
    Added Reference https://github.com/jupyterlab/jupyterlab/commit/cf6e89a8d315c4134cefa50c220bca296da466a7
    Added Reference https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.11
    Added Reference https://github.com/jupyterlab/jupyterlab/releases/tag/v4.6.4
    Added Reference https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-6966-vjj6-99xv
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.