CVE-2026-114135: Jupyter Server is the backend for Jupyter web applications

Routine

HIGH 8.8

CVE-2026-114135 is a high-severity flaw (CVSS 8.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Jupyter Server is the backend for Jupyter web applications. From 2.0.0 until 2.6.0, enabling GatewayClient.url replaced the normal KernelWebsocketHandler with WebSocketChannelsHandler, which authenticated the user but did not call authorizer.is_authorized(...) for the execute action on the kernels resource. A restricted authenticated user could therefore open an upstream kernel channel and obtain kernel execution despite the configured Authorizer

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 68%)
CISA exploited list	No
Weakness	CWE-862
Published	2026-10-21
Last modified	2026-10-22

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-10-21Published CVE record published
2026-10-22 17:21 UTCUpdated Record last modified

Exact fixes by distribution

Python (pip) · jupyter-server · FIXED · 2.6.0 · vulnerable: >= 2.0.0, < 2.6.0 · source

pip install --upgrade "jupyter-server>=2.6.0" pip show jupyter-server

Fedora ELN · ntpd-rs · FIXED · 1.7.2-3.eln159 · FEDORA-2026-57e4a99310 · source

sudo dnf upgrade --advisory=FEDORA-2026-57e4a99310

Fedora 46 · moby-engine · FIXED · 29.9.2-2.fc46 · FEDORA-2026-4856be87b3 · source

sudo dnf upgrade --advisory=FEDORA-2026-4856be87b3

Debian 12 · jupyter-server · NO FIX YET

Debian 13 · jupyter-server · NO FIX YET

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-114135?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-114135 being exploited?

CVE-2026-114135 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-114135 affect?

CVE-2026-114135 affects affected software. Severity is high (CVSS 8.8). Jupyter Server is the backend for Jupyter web applications. From 2.0.0 until 2.6.0, enabling GatewayClient.url replaced the normal KernelWebsocketHandler with WebSocketChannelsHandler, which authenticated the user but did not call authorize

How urgent is CVE-2026-114135?

Priority 39/100. High severity

Software pages

Jupyter vulnerabilities

References

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