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NVD / CVE Program· CNA GitHub_M

CVE-2026-73416: jupyterlab: PyPI extension blocklist package-name canonicalization bypass

Noroxi assessment

Priority: Monitor (action score 24/100)

  • 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: 0.66% (FIRST EPSS); higher than 52% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action 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 4.5.0 until 4.5.10 and 4.6.2, in jupyterlab/extensions/manager.py and jupyterlab/extensions/pypi.py, JupyterLab's PyPI extension manager enforces blocked_extensions_uris by comparing requested install names to blocklist entries with custom normalization that is weaker than PyPI package-name canonicalization. An authenticated user can request a PyPI-equivalent spelling such as JupyterLab.Git for a blocklisted package such as jupyterlab-git, and JupyterLab accepts the install request even though pip resolves the variant to the same package. Security impact requires an allowlist or blocklist intended to restrict package installation, the PyPI Extension Manager, and kernels and terminals that are disabled or delegated to remote hosts. The bypass lets an authenticated user install a prohibited extension, defeat integrity restrictions, and affect availability without gaining new read access. This issue is fixed in versions 4.5.10 and 4.6.2.

MediumCVSS 6.1 · v4.0—No exploit Fix available
Published
Aug 13, 2026
Updated
Sep 18, 2026
EPSS
0.6% · 52th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
6.1
NVD has not scored this yet; the score shown is the CNA’s.

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

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.

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When you'll hear from us

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  • 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.

—

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

    • >= 4.5.0, < 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 4.5.0 · 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-2026-73417JupyterLab: Cross-site scripting (XSS) via crafted settings file (`overrides.json`)
    34Monitor
  • 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

Published before and after this one in the same product

  • ← EarlierCVE-2026-73415Aug 12, 2026 · jupyterlab: Image viewer in JupyterLab allows XSS when opening malicious image in new browser tab
    30Monitor
  • ← EarlierCVE-2026-73627Aug 13, 2026 · JupyterLab 4.6.0 Plugin Manager Lock-Rule Enforcement 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.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

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

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-178 · Improper Handling of Case Sensitivity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:L/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-secondary

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (9 more)

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

All records