Description
NLTK from 3.2.5 before 3.10.4 contains an algorithmic complexity vulnerability in TreebankWordTokenizer.span_tokenize that allows remote attackers to cause quadratic CPU consumption through repeated list.pop(0) calls. Attackers can submit long runs of double-quote characters to services span-tokenizing untrusted text, exhausting a CPU core and degrading availability.
Metrics
CVSS 3.1 5.3/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
No affected versions have been published.
Timeline
- Published
- Nov 13, 2026
- Last modified
- Nov 13, 2026
- NVD status
- Awaiting Analysis