CVE-2026-54527: JupyterLab Git is a Git extension for JupyterLab

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CRITICAL 9.0UPGRADE

CVE-2026-54527 is a critical-severity flaw (CVSS 9.0) affecting jupyterlab-git. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.5% (top 56%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-07-08
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: jupyter

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-08 21:16 UTCPublished CVE record published
2026-10-25 17:10 UTCUpdated Record last modified

jupyter jupyterlab-git UPGRADE

Affected: >= 0.30.1 and < 0.54.0 · 0.30.0 · 0.30.0 beta3

Fixed in: 0.54.0

Safe to downgrade to: a release before 0.30.0

1. Check installed version

apt-cache policy jupyterlab-git || rpm -q jupyterlab-git || jupyterlab-git --version

2. UPGRADE to 0.54.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade jupyterlab-git

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade jupyterlab-git

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.30.0 (Debian / Ubuntu)

apt-cache madison jupyterlab-git sudo apt install jupyterlab-git=<VERSION_BEFORE_0.30.0> sudo apt-mark hold jupyterlab-git

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list jupyterlab-git sudo dnf downgrade jupyterlab-git-<VERSION_BEFORE_0.30.0> sudo dnf versionlock add jupyterlab-git

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-54527?

jupyterlab-git: upgrade to 0.54.0. Exact commands for each OS are on this page.

Is CVE-2026-54527 being exploited?

CVE-2026-54527 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-54527 affect?

CVE-2026-54527 affects jupyterlab-git. Severity is critical (CVSS 9.0). 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

How urgent is CVE-2026-54527?

Priority 48/100. Critical severity; Public exploit reference

Software pages

Git vulnerabilities · Jupyter vulnerabilities

Related CVEs

CVE-2026-54528 HIGH 7.1 UPGRADE JupyterLab Git is a Git extension for JupyterLab

References

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