CVE-2026-40864 JupyterHub: Cross-origin form POSTs bypass XSRF

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...