Origin Validation Error Affecting jupyter-server package, versions *


Severity

Recommended
low

Based on Debian security rating.

Threat Intelligence

EPSS
0.2% (10th percentile)

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  • Snyk IDSNYK-DEBIAN13-JUPYTERSERVER-17139931
  • published4 Jun 2026
  • disclosed3 Jun 2026

Introduced: 3 Jun 2026

CVE-2026-6657  (opens in a new tab)
CWE-346  (opens in a new tab)

How to fix?

There is no fixed version for Debian:13 jupyter-server.

NVD Description

Note: Versions mentioned in the description apply only to the upstream jupyter-server package and not the jupyter-server package as distributed by Debian. See How to fix? for Debian:13 relevant fixed versions and status.

A vulnerability in jupyter-server versions 1.12.0 through 2.17.0 allows an attacker to bypass CORS origin validation when the allow_origin_pat configuration is used. The issue arises from the use of re.match() for validating the Origin header, which only anchors at the start of the string. This allows attacker-controlled domains such as trusted.example.com.evil.com to pass validation against patterns intended to match trusted.example.com. The vulnerability affects multiple locations in the codebase, including CORS headers, WebSocket connections, referer validation, and login redirects, potentially enabling phishing attacks, arbitrary code execution, and unauthorized access to sensitive API responses.

CVSS Base Scores

version 3.1