medium3.7
CVE-2026-81723
NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment() that rescans accumulated XML fragments on ev…
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | nltk | <= 3.10.2 | 3.10.3 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-vp2x-qp44-57v7
- https://github.com/nltk/nltk/security/advisories/GHSA-vp2x-qp44-57v7
- https://nvd.nist.gov/vuln/detail/CVE-2026-81723
- https://github.com/nltk/nltk/commit/7808692d451b962711005d954859bb83aabcf8fa
- https://github.com/nltk/nltk/releases/tag/v3.10.3
- https://www.vulncheck.com/advisories/nltk-before-3.10.3-quadratic-cpu-exhaustion-via-xmlcorpusview