{"id":"CVE-2026-63312","title":"NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() directly instead of pathsec.open()","summary":"NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() directly instead of pathsec.open(). Attackers who control the fileid argument can r…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-22"],"published":"2026-08-22","updated":"2026-08-22","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63312","references":[{"url":"https://github.com/nltk/nltk/security/advisories/GHSA-x5ph-mj9p-rfr8","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nltk-streambackedcorpusview-bypasses-pathsec-enforce-arbitrary-file-read","label":"disclosure@vulncheck.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63312"},{"url":"https://github.com/nltk/nltk/pull/3588"},{"url":"https://github.com/nltk/nltk/commit/674ea75accdf08eca3782dee0a9c4ed7e0d0025b"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.0"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3730.yaml"},{"url":"https://github.com/advisories/GHSA-x5ph-mj9p-rfr8"},{"url":"https://github.com/nltk/nltk"}],"tags":["nvd","ghsa","pip","osv"],"ingestedAt":"2026-08-23T04:42:15.353Z","epss":0.00563,"epssPercentile":0.45337,"aliases":["GHSA-x5ph-mj9p-rfr8","PYSEC-2026-3730"],"ecosystem":"pip","vendor":"nltk","product":"nltk","affected":["nltk <= 3.9.4"],"patched":["nltk 3.10.0"],"slug":"CVE-2026-63312","body":"## Overview\n\nNLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() directly instead of pathsec.open(). Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting, including sensitive system files and application credentials.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-63312)\n\nAffected packages:\n\n- `nltk <= 3.9.4`\n\nPatched in:\n\n- `nltk 3.10.0`\n\nSource: https://github.com/advisories/GHSA-x5ph-mj9p-rfr8","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}