Is CVE-2026-114135 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-114135 being exploited in the wild.

How severe is CVE-2026-114135?

High severity, with a CVSS score of 8.8, published 21 October 2026.

Which products and versions are affected?

Jupyter Server 2.0.0 through 2.6.0; jupyter-server (PyPI) >= 2.0.0, < 2.6.0, ECOSYSTEM:introduced=2.0.0,fixed=2.6.0.

How is CVE-2026-114135 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-114135?

Check whether you run Jupyter Server or jupyter-server (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-114135: Jupyter Server authorization bypass in kernel gateway handlers

Q: Is there a fix for CVE-2026-114135?

Yes. jupyter-server (PyPI): upgrade to 2.6.0 or later. Until then: Avoid manually registering the deprecated jupyter_server.gateway.handlers module in deployments; use the default gateway configuration instead. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-114135 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-114135?

Check whether you run Jupyter Server or jupyter-server (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-114135 · Severity: high · CVSS 8.8 · Published 2026-10-21

Jupyter Server is the backend for interactive computing environments where users write and execute code. A flaw in versions 2.0.0 through 2.6.0 allows authenticated users to bypass authorization checks and execute code on kernels they should not have access to, potentially exposing sensitive data and credentials. Even after the fix, deployments that manually use deprecated gateway handlers remain vulnerable.

Technologies: Jupyter Server, jupyter-server (PyPI). Vendors: Jupyter, PyPI.

Quick answers

Is CVE-2026-114135 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-114135 being exploited in the wild.
How severe is CVE-2026-114135?: High severity, with a CVSS score of 8.8, published 21 October 2026.
Which products and versions are affected?: Jupyter Server 2.0.0 through 2.6.0; jupyter-server (PyPI) >= 2.0.0, < 2.6.0, ECOSYSTEM:introduced=2.0.0,fixed=2.6.0.
Is there a fix for CVE-2026-114135?: Yes. jupyter-server (PyPI): upgrade to 2.6.0 or later. Until then: Avoid manually registering the deprecated jupyter_server.gateway.handlers module in deployments; use the default gateway configuration instead. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-114135 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-114135?: Check whether you run Jupyter Server or jupyter-server (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

jupyter-server (PyPI): upgrade to 2.6.0 or later
```
pip install "jupyter-server>=2.6.0"
```

Avoid manually registering the deprecated jupyter_server.gateway.handlers module in deployments; use the default gateway configuration instead.

Technical details

The vulnerability is an authorization bypass in the GatewayClient and WebSocketChannelsHandler components where the authorizer.is_authorized() check for kernel execute actions was omitted. An authenticated attacker can open an upstream kernel channel without proper authorization checks, gaining arbitrary code execution privileges on the kernel. The default configuration is fixed in version 2.6.0, but manual use of the deprecated jupyter_server.gateway.handlers module bypasses the authorization fix.

Affected products

Jupyter Jupyter Server 2.0.0 through 2.6.0

Identifiers

CVE-2026-114135
GHSA-354v-3q48-cv69

Timeline

2026-10-21: disclosed

References

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