CVE-2026-81723
NLTK before 3.10.3 Quadratic CPU Exhaustion via XMLCorpusView
- State
- Published
- Severity
- 6.3 Medium
- Published
- Aug 27, 2026
- Updated
- Aug 31, 2026
- Reserved
- Aug 27, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.3 Medium | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 3.7 Low | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L | VulnCheck |
Weaknesses
- CWE-400 Uncontrolled Resource Consumption
Affected Products
| Product | Versions |
|---|---|
nltknltk |
|
References
- GitHub Security Advisory (GHSA-vp2x-qp44-57v7)vendor-advisory
- VulnCheck Advisory: NLTK before 3.10.3 Quadratic CPU Exhaustion via XMLCorpusViewthird-party-advisory
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