XSS in Jupyter Jupyterlab-Git
CVE-2026-54527
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.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.004 (29.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H.
Affected products
- Jupyter Jupyterlab-git — versions 0.30.0
- Jupyterlab Jupyterlab-git — versions >= 0.30.0b3, < 0.54.0
Weakness classification (CWE)
References
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-54527?
- CVE-2026-54527 is a critical-severity vulnerability in Jupyter Jupyterlab-Git, classified under Cross-site Scripting. CVSS score: 9.0/10. Published 2026-07-08.
- How severe is CVE-2026-54527?
- Critical severity. CVSS v3 base score is 9.0 out of 10.