CVE-2026-54527: Jupyter Jupyterlab-Git

Critical severity, CVSS 9.0. EPSS: 0.5% chance of exploitation in the next 30 days.

JupyterLab Git is a Git extension for JupyterLab. From 0.30.0b3 before 0.54.0, the PlainTextDiff.ts createHeader() method passes Git filenames directly to innerHTML when rendering renamed files in commit history, allowing a crafted filename to execute JavaScript when a victim views the rename diff in the Git History tab. This issue is fixed in version 0.54.0.

Affected products

• Jupyter Jupyterlab-Git: from 0.30.1, before 0.54.0 (fixed in 0.54.0); version 0.30.0 only

Published 2026-07-08. Last modified 2026-07-15.