CVE-2026-54528: jupyterlab-git excluded_paths Case-Sensitivity Bypass Allows Reading Excluded Directories

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-07-08 · updated 2026-10-25
Weakness: CWE-178

Description

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.

Affected products

jupyterlab-git: before 0.54.0 — fixed in 0.54.0

How to fix

Upgrade to a fixed version: jupyterlab-git 0.54.0. Check the vendor advisory for mitigations.

References

https://github.com/jupyterlab/jupyterlab-git/commit/460035275b5963dc96e364e60ba6a73717fbd033
https://github.com/jupyterlab/jupyterlab-git/releases/tag/v0.54.0
https://github.com/jupyterlab/jupyterlab-git/security/advisories/GHSA-436q-jwfr-rm2h
https://github.com/jupyterlab/jupyterlab-git/security/advisories/GHSA-436q-jwfr-rm2h

Get alerted when CVE-2026-54528 or the next vulnerability affects your stack