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NVD / CVE Program· CNA GitHub_M

CVE-2026-73417: JupyterLab: Cross-site scripting (XSS) via crafted settings file (`overrides.json`)

HighCVSS 8.6 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 34/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.74% (FIRST EPSS); higher than 55.3% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No special conditions are required; it is repeatable.
  • Fixed version: jupyterlab (Debian:14) 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-4; python-jupyterlab (openSUSE:Tumbleweed) 4.5.10-1.1; jupyterlab (PyPI) 4.5.10, 4.6.2.

Low priority for now. Upgrade to jupyterlab (Debian:14) 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-4; python-jupyterlab (openSUSE:Tumbleweed) 4.5.10-1.1; jupyterlab (PyPI) 4.5.10, 4.6.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 3.3.0 until 4.5.10 and 4.6.2, JupyterLab allows notebook settings to be shared and applied through an overrides.json file using the Import button in the Settings Editor. In packages/notebook-extension/schema/tracker.json and packages/notebook-extension/src/index.ts, the sideBySideLeftMarginOverride and sideBySideRightMarginOverride settings are not properly validated before being inserted into style content, allowing a crafted settings file to contain instructions that execute as code instead of only changing display preferences. A user can import the malicious file, or an attacker with access to a shared settings location can plant an overrides.json that is applied automatically. The embedded code runs with the affected user's access and can read or modify notebooks and files and run code through the notebook server, including on a connected kernel. This issue is fixed in versions 4.5.10 and 4.6.2.

Published
Aug 13, 2026
Updated
Sep 18, 2026
EPSS
0.7% · 55th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.6
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-73417

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • jupyterlab jupyterlab

    • >= 3.3.0, < 4.5.10, >= 4.6.0, < 4.6.2affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:13jupyterlabfrom 0—
Debian:14jupyterlabbefore 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-44.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-4
openSUSE:Tumbleweedpython-jupyterlabbefore 4.5.10-1.14.5.10-1.1
PyPIjupyterlabfrom 3.3.0 · before 4.5.104.5.10
PyPIjupyterlabfrom 4.6.0 · before 4.6.24.6.2

Same product

jupyterlab: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-102831JupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard
    32Monitor
  • CVE-2026-73626JupyterLab before 4.6.2 Authentication Bypass via PyPIExtensionManager
    30Monitor
  • CVE-2026-73415jupyterlab: Image viewer in JupyterLab allows XSS when opening malicious image in new browser tab
    30Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-73627Aug 13, 2026 · JupyterLab 4.6.0 Plugin Manager Lock-Rule Enforcement Bypass
    24Monitor
  • ← EarlierCVE-2026-73416Aug 13, 2026 · jupyterlab: PyPI extension blocklist package-name canonicalization bypass
    24Monitor
  • Later →CVE-2026-102830Sep 29, 2026 · JupyterLab: Cross-site scripting (XSS) in JupyterLab via crafted language package (jupyterlab.json)
    27Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:jupyterlab4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-4 · Debian:14Package registry (OSV)
opensuse:python-jupyterlab4.5.10-1.1 · openSUSE:TumbleweedPackage registry (OSV)
PyPI:jupyterlab4.5.10Package registry (OSV)
PyPI:jupyterlab4.6.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-10283147 days apartJupyterLab: Cross-site scripting (XSS) in JupyterLab via notebook cells pasted from the system clipboard
    32Monitor
  • CVE-2026-734151 days apartjupyterlab: Image viewer in JupyterLab allows XSS when opening malicious image in new browser tab
    30Monitor
  • CVE-2026-10283047 days apartJupyterLab: Cross-site scripting (XSS) in JupyterLab via crafted language package (jupyterlab.json)
    27Monitor

Not on record for this CVE: researcher credit · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
A
Scope
X

Weakness class (CWE)

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:L/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-secondary

Root cause

User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

The bug in code

The whole CWE-79 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
commentEl.textContent = comment.body;

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (9 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records