CVE-2026-42266

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

5.65% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 92.9% of scored records. A rank, not a probability.

NVD base score

8.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-08-28.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-05-13 15:08Z5 MO AGO

Last updated

2026-08-28 12:04Z2 MO AGO

Reserved

2026-04-26

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

High (CVSS 8.8)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')Base
• CWE-602Client-Side Enforcement of Server-Side SecurityClass

Data version

5.2

Document digest

d5d29e41a2ba38d9f73c6dd542936a59f1e8df860be28aa206b6836a59947964

• github.comhttps://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4x_refsource_CONFIRM
• github.comhttps://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7x_refsource_MISC
• jupyterhub.readthedocs.iohttps://jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.htmlx_refsource_MISC
• jupyterlab.readthedocs.iohttps://jupyterlab.readthedocs.io/en/latest/user/extensions.html#extension-manager-implementationsx_refsource_MISC
• access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-42266vdb-entryx_refsource_REDHAT
• bugzilla.redhat.comRHBZ#2477072https://bugzilla.redhat.com/show_bug.cgi?id=2477072issue-trackingx_refsource_REDHAT
• security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42266.jsonx_sadp-csaf-vex
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:43038vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:60520vendor-advisoryx_refsource_REDHAT