{"apiVersion":"1.0","identifier":"CVE-2026-81727","description":"NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incr_download methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader directory can create hardlinks pointing to outside-root files that are then overwritten during normal package extraction, mutating files outside the intended install tree.","publishedAt":"2026-08-27T17:21:03","lastModifiedAt":"2026-08-27T20:18:55","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-81727","cvssScore":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","epssProbability":0.00137,"riskScore":0.72,"affectedProduct":"NLTK","affectedVersions":"<3.10.3","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-81727","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-81727","en":"https://www.redsauce.net/en/cves/CVE-2026-81727","fr":"https://www.redsauce.net/fr/cves/CVE-2026-81727","pt":"https://www.redsauce.net/pt/cves/CVE-2026-81727","de":"https://www.redsauce.net/de/cves/CVE-2026-81727","sk":"https://www.redsauce.net/sk/cves/CVE-2026-81727","el":"https://www.redsauce.net/el/cves/CVE-2026-81727"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-81727"}}