{"action":"Upgrade nltk to 3.10.0 or later.","affected":[{"fixed":"3.10.0","introduced":"0"}],"component":"nltk","cve_ids":["CVE-2026-12261"],"ecosystem":"PyPI","epss":0.00211,"exploited":false,"fixed_versions":["3.10.0"],"ghsa_id":"GHSA-ffj6-66c4-86gw","id":"tcs_01M5KH8WW9M4Y2416VH06ZBYA9","modified_at":"2026-10-15T14:45:11.781131372Z","published_at":"2026-08-07T07:16:26.377Z","references":["https://osv.dev/vulnerability/PYSEC-2026-3954","https://huntr.com/bounties/8b8c381e-08a8-4e4f-bb46-a320c96a364f","https://github.com/advisories/GHSA-ffj6-66c4-86gw"],"severity":{"label":"medium","score":6.5},"sources":[{"source":"osv","source_id":"PYSEC-2026-3954","url":"https://osv.dev/vulnerability/PYSEC-2026-3954"}],"summary":"A vulnerability in `nltk.downloader` in nltk/nltk versions <= 3.9.4 allows for cross-package resource and model poisoning. The downloader extracts package archives into shared namespaces such as `corp"}