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Fencer Vulns
critical 9.0

CVE-2026-54527 json

JupyterLab Git: Stored XSS leading to RCE

published 2026-06-19 4 mo ago modified 2026-10-25 14 d ago also GHSA-f962-v9hr-pfg5 , PYSEC-2026-2540 , PYSEC-2026-2541 , EUVD-2026-42428

cvss
9.0
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi jupyterlab-git 0.54.0
  • pypi jupyterlab-git-core 0.54.0
  • npm @jupyterlab/git 0.54.0
  • jupyter jupyterlab-git 0.54.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-54527 updated cvss 9.0

jupyterlab-git: jupyterlab-git-core: @jupyterlab/git: JupyterLab Git: Remote Code Execution via crafted Git filenames in commit history

  • Red Hat OpenShift AI (RHOAI) rhoai/odh-th06-cpu-torch210-py312-rhel9, rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-rocm64-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch210-py312-rhel9, rhoai/odh-th06-cuda130-torch291-py312-rhel9, rhoai/odh-workbench-jupyter-minimal-cpu-py312-rhel9, +4 more
    affected: no fix available
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-th-torch-cpu-py312-rhel9, rhoai/odh-th-torch-cuda-py312-rhel9, rhoai/odh-th-torch-rocm-py312-rhel9, rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9, rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9, rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9, +2 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jupyterlab/jupyterlab-git/security/advisories/GHSA-f962-v9hr-pfg5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 9.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
GitHub 3.1 9.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi jupyterlab-git
>=0.30.0b3, <0.54.0
0.54.0
pypi jupyterlab-git-core
>=0.30.0b3, <0.54.0
0.54.0
npm @jupyterlab/git
>=0.30.0-beta.3, <0.54.0
0.54.0

Affected products

  • jupyterlab jupyterlab-git

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.