nltk: Arbitrary File Read via Path Traversal in nltk.data.load() through Percent-Encoded Sequences

Date Aug 13, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product PyPI ยท nltk
CVE CVE-2026-12243
High-risk advisory CVE-2026-12243

Summary

nltk: Arbitrary File Read via Path Traversal in nltk.data.load() through Percent-Encoded Sequences

Why it matters

GitHub has published a reviewed security advisory for nltk. Prioritize it with other application dependency updates, especially because EPSS places it in the 45% percentile.

Operator check

Check whether nltk is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. EPSS probability: 0.6%; percentile: 45%.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.