{"id":"GHSA-cv2g-m8rr-888c","summary":"Duplicate Advisory: Natural Language Toolkit (NLTK) has unbounded recursion in JSONTaggedDecoder.decode_obj() may cause DoS","details":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-rf74-v2fm-23pw. This link is maintained to preserve external references.\n\n## Original Description\nNLTK versions before 3.9.4 contain an unbounded recursion vulnerability in JSONTaggedDecoder.decode_obj() that allows attackers to cause denial of service by supplying deeply nested JSON structures. Attackers can craft JSON payloads exceeding the recursion limit to trigger an unhandled RecursionError that crashes the Python process.","modified":"2026-09-10T03:51:13.899979725Z","published":"2026-08-22T15:31:03Z","withdrawn":"2026-09-02T15:33:17Z","database_specific":{"cwe_ids":["CWE-674"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-09-02T15:33:17Z","nvd_published_at":"2026-08-22T15:16:19Z"},"references":[{"type":"WEB","url":"https://github.com/nltk/nltk/security/advisories/GHSA-rf74-v2fm-23pw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66393"},{"type":"PACKAGE","url":"https://github.com/nltk/nltk"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/nltk-before-denial-of-service-via-jsontaggeddecoder"}],"affected":[{"package":{"name":"nltk","ecosystem":"PyPI","purl":"pkg:pypi/nltk"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.9.3"}]}],"versions":["0.8","0.9","0.9.3","0.9.4","0.9.5","0.9.6","0.9.7","0.9.8","0.9.9","2.0.1","2.0.1rc1","2.0.1rc2-git","2.0.1rc3","2.0.1rc4","2.0.2","2.0.3","2.0.4","2.0.5","2.0b4","2.0b5","2.0b6","2.0b7","2.0b8","2.0b9","3.0.0","3.0.0b1","3.0.0b2","3.0.1","3.0.2","3.0.3","3.0.4","3.0.5","3.1","3.2","3.2.1","3.2.2","3.2.3","3.2.4","3.2.5","3.3","3.4","3.4.1","3.4.2","3.4.3","3.4.4","3.4.5","3.5","3.5b1","3.6","3.6.1","3.6.2","3.6.3","3.6.4","3.6.5","3.6.6","3.6.7","3.7","3.8","3.8.1","3.9","3.9.1","3.9.2","3.9.3","3.9b1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-cv2g-m8rr-888c/GHSA-cv2g-m8rr-888c.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}