{"id":"CVE-2026-78682","revision":"ad1a74f01f064ae09223d22d0670779c","records":[{"revision":"ad1a74f01f064ae09223d22d0670779c","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-78682","aliases":[],"title":"NLTK before 3.10.3 SSRF Protection Bypass via Proxy","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. An attacker can supply a validated public URL that the proxy forwards to an internal loopback-only service, allowing disclosure of internal HTTP resources, loading of forged downloader indexes, and installation of attacker-chosen package content.","state":0,"publishedAt":"2026-08-25T01:30:38.486+00:00","modifiedAt":"2026-10-08T15:25:10.277+00:00","affected":[{"ecosystem":"Vendor product","name":"nltk","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"nltk\",\n                    \"product\": \"nltk\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"versions\": [\n                        {\n                            \"version\": \"0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\",\n                            \"lessThan\": \"3.10.3\"\n                        },\n                        {\n                            \"version\": \"3.10.3\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"packageURL\": \"pkg:pypi/nltk\"\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","score":8.7,"severity":"HIGH"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5,"severity":"HIGH"}],"references":["https://github.com/nltk/nltk/security/advisories/GHSA-6ww7-3frv-cqxh","https://www.vulncheck.com/advisories/nltk-before-ssrf-protection-bypass-via-proxy"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-78682","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-78682","identifiers":["CVE-2026-78682"]},"retained":false,"historicalAffected":[]}],"coverage":[]}