Threats tagged 'ghsa-v42x-x7jp-845h'

CVE-2026-6657 is a medium severity vulnerability in jupyter-server versions 1.12.0 through 2.17.0 that allows bypassing of CORS origin validation when the allow_origin_pat configuration is used. The issue stems from improper use of re.match() for Origin header validation, which only anchors at the start of the string, enabling attacker-controlled domains that mimic trusted domains to bypass checks. This affects multiple code locations including CORS headers, WebSocket connections, referer validation, and login redirects, potentially leading to phishing, unauthorized access, and arbitrary code execution.