Is CVE-2026-81723 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-81723?

CVE-2026-81723 has a CVSS v3 severity of LOW (3.7).

Back

CVE-2026-81723

Description

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.