CVE-2026-70626: Nltk

Medium severity, CVSS 6.2. EPSS: 0.2% chance of exploitation in the next 30 days.

NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place symlinks inside the corpus root to access files outside the intended boundary.

Affected products

• Nltk Nltk: before 3.9.4 (fixed in 3.9.4)

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