CVE-2026-81723

EUVD-2026-67073
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
3.7 LOW
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: 12.56%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
nltknltk
𝑥
< 3.10.3
CNA
Debian logo
Debian Releases
Debian Product
Codename
nltk
bookworm
vulnerable
bullseye
vulnerable
forky
3.10.3-1
fixed
sid
3.10.3-1
fixed
trixie
no-dsa
Common Weakness Enumeration
References
https://github.com/nltk/nltk/security/advisories/GHSA-vp2x-qp44-57v7
https://www.vulncheck.com/advisories/nltk-before-3.10.3-quadratic-cpu-exhaustion-via-xmlcorpusview