CVE-2026-78682 NLTK before 3.10.3 SSRF Protection Bypass via Proxy

NLTK before 3.10.3 contains a server-side request forgery vulnerability in nltk.pathsec.urlopen and callers nltk.data.load, nltk.downloader.Downloader.index/download when an HTTP proxy is configured. pathsec.urlopen validates the requested hostname locally, but proxy-handler inheritance disables...