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 denying that action, exposing data and credentials available to the kernel and permitting modification or disruption of the kernel environment. The default gateway configuration is fixed in version 2.6.0. In 2.6.0 and later, the same authorization bypass remains possible when a deployment manually registers the deprecated jupyter_server.gateway.handlers module, because its handler still omits the configured kernel-execute authorization decision.
Metrics
Affected Vendors & Products
References
History
Wed, 28 Oct 2026 02:30:00 +0000
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ssvc
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Thu, 22 Oct 2026 12:30:00 +0000
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| Weaknesses | CWE-425 | |
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threat_severity
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threat_severity
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Thu, 22 Oct 2026 10:45:00 +0000
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Jupyter
Jupyter jupyter Server |
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| Vendors & Products |
Jupyter
Jupyter jupyter Server |
Wed, 21 Oct 2026 20:15:00 +0000
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| Description | 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 denying that action, exposing data and credentials available to the kernel and permitting modification or disruption of the kernel environment. The default gateway configuration is fixed in version 2.6.0. In 2.6.0 and later, the same authorization bypass remains possible when a deployment manually registers the deprecated jupyter_server.gateway.handlers module, because its handler still omits the configured kernel-execute authorization decision. | |
| Title | Jupyter Server: Gateway WebSocket handler bypasses kernel execute authorization | |
| Weaknesses | CWE-862 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-10-21T19:58:51.544Z
Updated: 2026-10-28T01:36:08.532Z
Reserved: 2026-10-20T21:53:58.473Z
Link: CVE-2026-114135
Updated: 2026-10-28T01:36:01.101Z
Status : Awaiting Analysis
Published: 2026-10-21T20:17:25.407
Modified: 2026-10-28T02:17:05.233
Link: CVE-2026-114135