Skip to content
Fencer Vulns
high 8.8

CVE-2026-42557 json

jupyterlab: Command linker attributes in HTML enable one-click command execution from untrusted content

published 2026-05-06 6 mo ago modified 2026-10-25 14 d ago also BIT-jupyter-base-notebook-2026-42557 , BIT-jupyter-notebook-2026-42557 , BIT-jupyterlab-2026-42557 , EUVD-2026-30000 , GHSA-mqcg-5x36-vfcg , PYSEC-2026-2537 , PYSEC-2026-2681

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.

Patch / fix

  • pypi jupyterlab 4.5.7
  • pypi notebook 7.5.6
  • bitnami jupyter-base-notebook 7.5.6
  • bitnami jupyter-notebook 7.5.6
  • bitnami jupyterlab 4.5.7
  • Red Hat Red Hat Migration Toolkit for Applications 8.2 1784109883
  • Red Hat Red Hat OpenShift AI 3.4 1787073546, 1787073593, 1787073605, 1787073713, 1787073717, 1787073913, 1787073929, 1787074078, 1787074331, 1787076481, 1787076778, 1787077779
  • jupyterlab Debian 14 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3

debian advisories DEBIAN-CVE-2026-42557

  • python-jupyterlab openSUSE Tumbleweed 4.5.7-1.1
  • python-notebook openSUSE Tumbleweed 7.5.6-1.1

opensuse advisories openSUSE-SU-2026:10748-1openSUSE-SU-2026:10749-1

  • jupyter-notebook Alpine 3.24 7.5.6-r0

alpine advisories ALPINE-CVE-2026-42557

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2026-42557 updated cvss 8.8

jupyterlab: JupyterLab: Arbitrary code execution via deceptive button in HTML output

  • Red Hat OpenShift AI (RHOAI) rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9
    affected: workaround, no fix available
  • Red Hat Migration Toolkit for Applications 8.2 mta/mta-solution-server-rhel9 1784109883
    fixed: vendor fix RHSA-2026:43038
  • Red Hat OpenShift AI 3.4 rhoai/odh-th06-cpu-torch210-py312-rhel9 1787076778, rhoai/odh-th06-rocm64-torch291-py312-rhel9 1787076481, rhoai/odh-th06-cuda130-torch210-py312-rhel9 1787077779, rhoai/odh-workbench-jupyter-minimal-cpu-py312-rhel9 1787073913, rhoai/odh-workbench-jupyter-minimal-cuda-py312-rhel9 1787074078, rhoai/odh-workbench-jupyter-minimal-rocm-py312-rhel9 1787073929, +6 more
    fixed: vendor fix RHSA-2026:60520
  • Red Hat Migration Toolkit for Applications 8.2 mta/mta-ui-rhel9 1783962515, mta/mta-cli-rhel9 1784211378, mta/mta-hub-rhel9 1784059743, mta/mta-rhel9-operator 1784219586, mta/mta-operator-bundle 1784220119, mta/mta-analyzer-addon-rhel9 1784163267, +7 more
    not affected: vulnerable code not present
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch291-py312-rhel9
    not affected: component not present
  • Red Hat OpenShift AI 3.4 rhoai/odh-cli-rhel9 1787330837, rhoai/rhai-cli-rhel9 1787330837, rhoai/odh-automl-rhel9 1786612415, rhoai/odh-mlflow-rhel9 1787226790, rhoai/odh-autorag-rhel9 1786612637, rhoai/odh-trainer-rhel9 1787089049, +88 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
none
Automatable
no
Technical impact
total
Assessed
5 mo ago

Exploit prediction

0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
GitHub 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CNA 4.0 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/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 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
OSV 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi jupyterlab
<4.5.7
4.5.7
pypi notebook
>=7.0.0, <7.5.6
7.5.6
bitnami jupyter-base-notebook
>=7.0.0, <7.5.6
7.5.6
bitnami jupyter-notebook
>=7.0.0, <7.5.6
7.5.6
bitnami jupyterlab
<4.5.7
4.5.7

Affected products

  • jupyterlab jupyterlab
  • jupyter notebook
  • Red Hat Red Hat Migration Toolkit for Applications 8.2
  • Red Hat Red Hat OpenShift AI 3.4
  • Red Hat Red Hat OpenShift AI (RHOAI)

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.