---
id: CVE-2026-114135
title: >-
  Jupyter Server: Gateway WebSocket handler bypasses kernel execute
  authorization
summary: >-
  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
  author…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-862
  - CWE-425
vendor: jupyter-server
product: jupyter_server
affected:
  - 'jupyter_server >= 2.0.0, < 2.6.0'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-28T01:35:54.216341Z'
published: '2026-10-21'
updated: '2026-10-28'
sourceUpdated: '2026-10-28T01:36:08.532Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114135'
references:
  - url: >-
      https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-354v-3q48-cv69
    label: >-
      https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-354v-3q48-cv69
  - url: 'https://github.com/jupyter-server/jupyter_server/pull/1261'
    label: 'https://github.com/jupyter-server/jupyter_server/pull/1261'
  - url: >-
      https://github.com/jupyter-server/jupyter_server/commit/35ffe5d435682128da16dc144a8e9e9f8fa85dd8
    label: >-
      https://github.com/jupyter-server/jupyter_server/commit/35ffe5d435682128da16dc144a8e9e9f8fa85dd8
  - url: 'https://github.com/jupyter-server/jupyter_server/releases/tag/v2.6.0'
    label: 'https://github.com/jupyter-server/jupyter_server/releases/tag/v2.6.0'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-114135.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-114135'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2558527'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-114135'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-114135'
  - url: 'https://github.com/jupyter-server/jupyter_server'
  - url: 'https://github.com/advisories/GHSA-354v-3q48-cv69'
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
  - osv
  - pip
  - ghsa
epss: 0.00484
epssPercentile: 0.41503
aliases:
  - GHSA-354v-3q48-cv69
ecosystem: pip
patched:
  - jupyter-server 2.6.0
ingestedAt: '2026-10-21T20:11:44.902Z'
---

## Overview

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.

## Affected

- `jupyter_server >= 2.0.0, < 2.6.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-114135)

Affected packages:

- `jupyter-server >= 2.0.0, < 2.6.0`

Patched in:

- `jupyter-server 2.6.0`

Source: https://osv.dev/vulnerability/GHSA-354v-3q48-cv69

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat OpenShift AI (RHOAI) · no fix planned: Red Hat OpenShift AI (RHOAI) · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-114135.json)