CVE-2026-114135 Jupyter Server - Authorization Bypass

Jupyter Server 2.0.0 to 2.6.0 contains an authorization bypass caused by GatewayClient.url replacing KernelWebsocketHandler with WebSocketChannelsHandler that skips execute action authorization, letting restricted authenticated users execute kernel code, exploit requires enabling GatewayClient.url or using deprecated gateway handlers.

CVSS base score 8.8 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
View the NVD record ↗

Details

Type
Authorization Bypass
Impact
Privilege Escalation, Data Tampering, Information Disclosure
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published
21 October 2026
Updated
22 October 2026
Weakness
CWE-862

Vendor fix

Upgrade to version 2.6.0 or later and avoid using deprecated jupyter_server.gateway.handlers module.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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