What is CVE-2026-54528?

CVE-2026-54528 is a high-severity vulnerability in Jupyter Jupyterlab-Git, classified under Improper Handling of Case Sensitivity. CVSS score: 7.1/10. Published 2026-07-08.

How severe is CVE-2026-54528?

High severity. CVSS v3 base score is 7.1 out of 10.

Vulnerability in Jupyter Jupyterlab-Git

CVE-2026-54528

JupyterLab Git is a Git extension for JupyterLab. Prior to 0.54.0, jupyterlab-git uses fnmatch.fnmatchcase() in GitHandler.prepare() in jupyterlab_git/handlers.py to enforce excluded_paths, allowing an authenticated user on a case-insensitive filesystem to vary URL path casing and read excluded directories. This issue is fixed in version 0.54.0.

Published 2026-07-08 · last modified 2026-07-15.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.3th percentile), scored 2026-10-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Jupyter Jupyterlab-Git
Jupyterlab Jupyterlab-Git — versions < 0.54.0

Weakness classification (CWE)

CWE-178 — Improper Handling of Case Sensitivity

References

github.com/jupyterlab/jupyterlab-git/commit/460035275b5963dc96e364e60ba6a73717f… (Patch)
github.com/jupyterlab/jupyterlab-git/releases/tag/v0.54.0 (Release Notes)
github.com/jupyterlab/jupyterlab-git/security/advisories/GHSA-436q-jwfr-rm2h (Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-54528?: CVE-2026-54528 is a high-severity vulnerability in Jupyter Jupyterlab-Git, classified under Improper Handling of Case Sensitivity. CVSS score: 7.1/10. Published 2026-07-08.
How severe is CVE-2026-54528?: High severity. CVSS v3 base score is 7.1 out of 10.