CVE-2026-42266
high
CVSS v3
8.8
CVSS v4 NEW
—
VIR risk
8.8
Description
JupyterLab has an Extension Manager API/GUI Policy Discrepancy, allowing 3rd party (malicious) extensions install via POST request
Predictions
Exploit likelihood
92%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Affected 3 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Affected | — |
| forky | Affected | — |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | jupyterlab | >=4.0.0,<4.5.7 | 4.5.7 |
| PIP | jupyterlab | >= 4.0.0, <= 4.5.6 | 4.5.7 |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| jupyter | jupyterlab | {"startIncluding":"4.0.0","endExcluding":"4.5.7"} | 4.5.7 |
References
- https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4
- https://nvd.nist.gov/vuln/detail/CVE-2026-42266
- https://github.com/jupyterlab/jupyterlab
- https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7
- https://jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html
- https://jupyterlab.readthedocs.io/en/latest/user/extensions.html#extension-manager-implementations
- https://security-tracker.debian.org/tracker/CVE-2026-42266
- https://github.com/advisories/GHSA-37w4-hwhx-4rc4
CWEs
CWE-88 CWE-602
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.