CVE Catalog
CVE-2026-81723
LowCVSS 3.7Summary
NLTK before 3.10.3 has a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment(). Malformed XML files can cause severe CPU consumption and DoS.
Risk Assessment
DoS attacks can overload the system and cause unavailability of NLTK-based services.
Recommendation
Upgrade NLTK to version 3.10.3 or later.
Original NVD description (English source)
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.