Jupyter Server: Gateway WebSocket handler bypasses kernel execute authorization

Summary Jupyter Server's gateway WebSocket handler checks that a user is authenticated, but it does not ask the configured Authorizer whether that user may execute kernels. In Jupyter Server 2.0.0 through 2.5.0, enabling GatewayClient.url automatically replaced the normal kernel channel handler...

GHSA-354V-3Q48-CV69 Jupyter Server: Gateway WebSocket handler bypasses kernel execute authorization

Summary Jupyter Server's gateway WebSocket handler checks that a user is authenticated, but it does not ask the configured Authorizer whether that user may execute kernels. In Jupyter Server 2.0.0 through 2.5.0, enabling GatewayClient.url automatically replaced the normal kernel channel handler...

CVE-2026-114135

Jupyter Server (versions 2.0.0 through 2.6.0) is vulnerable to an authorization bypass when GatewayClient.url is enabled. The WebSocketChannelsHandler fails to call authorizer.is_authorized(...) for the execute action on the kernels resource, allowing a restricted authenticated user to open an up...

CVE-2026-114135 Jupyter Server: Gateway WebSocket handler bypasses kernel execute authorization

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.isauthorized... for the execute action on the kernels...