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Vulnerabilities

Security fix · CVE-2026-114135

Jupyter Server is the backend for Jupyter web applications.

Published Oct 21, 2026 · catalog updated Oct 28, 2026 · Jupyter Server is the

Last checked Nov 3, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-114135. EPSS is 0.48%. Act only if a listed version of Jupyter Server is the is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Jupyter Server is the).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High8.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.48%
Remediation
Advisory link
Affected products
package pip · pypi jupyter-server

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • package pipversion unspecified
  • pypi jupyter-serverversion unspecified

How to fix CVE-2026-114135

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-114135. EPSS is 0.48%. Act only if a listed version of Jupyter Server is the is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-862: Missing Authorization. EPSS 0.48%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 21, 2026 · NIST NVD

    Detected

    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

  2. Oct 28, 2026 · NIST NVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2026-114135

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-114135

    30-day exploitation probability 0.48%

    first.org
  • GitLab Advisory DatabasePackage advisoryCVE-2026-114135

    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 with this gateway-specific handler. An authenticated user who is denied the execute action on the kernels resour

    advisories.gitlab.com
  • NIST NVDVulnerability recordCVE-2026-114135

    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 act

    nvd.nist.gov
  • Snyk Vulnerability DatabasePackage advisorySNYK-PYTHON-JUPYTERSERVER-21431473

    Missing Authorization

    security.snyk.io
  • Tenable CVE DatabaseVulnerability recordCVE-2026-114135

    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

    tenable.com

References

Freshness

Last verified in this catalog Nov 3, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 3, 2026
  • Tenable CVE DatabaseOct 28, 2026
  • NIST NVDOct 28, 2026
  • Snyk Vulnerability DatabaseOct 25, 2026
  • GitLab Advisory DatabaseOct 23, 2026
  • CVE.orgOct 22, 2026