{"schemaVersion":3,"id":"CVE-2026-78682","aliases":["GHSA-6ww7-3frv-cqxh","PYSEC-2026-3733","DEBIAN-CVE-2026-78682"],"status":"published","duplicateOf":null,"title":null,"description":"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 the safe HTTP/HTTPS handlers so the actual fetch is performed by the proxy against a destination that is never re-validated. 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