CVE-2026-114135
Description
A flaw was found in jupyter-server. When configured with a gateway connection, the server validates user authentication but fails to verify whether the user has permission to run actions on computational kernels. A remote authenticated user with restricted privileges can exploit this flaw to open an unauthorized communication channel to an active kernel. This issue allows an attacker to execute arbitrary code, access sensitive credentials and data, or disrupt server environments.
Statement
This vulnerability is rated as having Important impact because authenticated users with restricted privileges can bypass authorization controls to execute arbitrary commands within computational kernels. The flaw specifically manifests when Jupyter Server is configured to route traffic through an external gateway, substituting the standard request handler with a websocket channel handler that omits kernel execution checks. Deployments that do not utilize remote gateway configurations or custom restrictive authorizers are not exposed to unauthorized execution through this mechanism.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Access Control
Technical Impact: Read Application Data; Modify Application Data; Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity
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