CVE-2026-42266: jupyter jupyterlab Argument Injection
Vulnerability summary
CVE-2026-42266 is a high (CVSS 8.8) Argument Injection vulnerability in jupyter jupyterlab. EPSS estimates a 0.85% chance of exploitation in the next 30 days, higher than 57.5% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 1 · Related 2Timeline
- 13-05-2026PublishedVulnerability first disclosed.
- 28-08-2026Last modifiedVulnerability information updated.
Description
JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager (allowed_extensions_uris) is not correctly enforced by JupyterLab. The PyPI Extension Manager was not contained to packages listed on the default PyPI index. This vulnerability is fixed in 4.5.7.
CVSS metrics
6 scores · 6 sources · 1 version- OSV · PypiEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · ChainguardEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.85%
Chance of exploitation in the next 30 days
Percentile
58%
Versus all other CVEs
30-day change
+0.22 pp
From 0.63% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
- CWE-602Client-Side Enforcement of Server-Side SecurityThe product is composed of a server that relies on the client to implement a mechanism that is intended to protect the server.
Affected systems
Chainguard2 products
- datahub-ingestion< 1.5.0.4-r0
- datahub-ingestion-fips< 1.5.0.1-r2
Debian1 product
- jupyterlabAll versions (No fix recorded) | < 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3
Jupyter1 product
- jupyterlab≥ 4.0.0, < 4.5.7
Jupyterlab1 product
- jupyterlab≥ 4.0.0, < 4.5.7
PyPI1 product
- jupyterlab≥ 4.0.0, < 4.5.7
Ubuntu1 product
- jupyterlabAll versions (No fix recorded)
6 vendors · 7 products
References
16 links- github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4X Refsource CONFIRMWEBAdvisoryREPORTMitigationVendor Advisory
