CVE-2026-81723

Summary

NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment() that rescans accumulated XML fragments on every 1 KiB block read. Attackers can provide malformed XML corpus files to cause severe CPU consumption and denial of service through affected readers like BNCCorpusReader.

Affected Software

VendorProductVersion RangeStatus
nltknltk0 < 3.10.3affected
nltknltk3.10.3unaffected

Weaknesses

  • CWE-400: Uncontrolled Resource Consumption

References