jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 3.3.0 until 4.5.10 and 4.6.2, JupyterLab allows notebook settings to be shared and applied through an overrides.json file using the Import button in the Settings Editor. In packages/notebook-extension/schema/tracker.json and packages/notebook-extension/src/index.ts, the sideBySideLeftMarginOverride and sideBySideRightMarginOverride settings are not properly validated before being inserted into style content, allowing a crafted settings file to contain instructions that execute as code instead of only changing display preferences. A user can import the malicious file, or an attacker with access to a shared settings location can plant an overrides.json that is applied automatically. The embedded code runs with the affected user's access and can read or modify notebooks and files and run code through the notebook server, including on a connected kernel. This issue is fixed in versions 4.5.10 and 4.6.2.
https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-pppj-hq3g-57pj
https://github.com/jupyterlab/jupyterlab/releases/tag/v4.7.0a1
https://github.com/jupyterlab/jupyterlab/releases/tag/v4.6.2
https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.10
https://github.com/jupyterlab/jupyterlab/pull/19186
https://github.com/jupyterlab/jupyterlab/pull/19185
https://github.com/jupyterlab/jupyterlab/pull/19184
https://github.com/jupyterlab/jupyterlab/commit/f1beab4a2027af4719d6edc07d52d6cf5a39a432
https://github.com/jupyterlab/jupyterlab/commit/be9303f5bcd5308eaeae953c5a3c903046682c2c
https://github.com/jupyterlab/jupyterlab/commit/9365f020baec5221deaf11535ed554c06637c999
Published: 2026-08-13
Updated: 2026-08-14
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 8.6
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:L
Severity: High
EPSS: 0.00552