CVE-2026-63312: Nltk

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

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 read arbitrary local files regardless of the ENFORCE setting, including sensitive system files and application credentials.

Affected products

• Nltk Nltk: before 3.10.0 (fixed in 3.10.0)

Published 2026-08-22. Last modified 2026-08-31.