CVE-2026-126301
NLTK from 3.6 before 3.10.4 contains an algorithmic complexity vulnerability in LegalitySyllableTokenizer.tokenize that allows remote attackers to exhaust CPU by supplying long all-vowel tokens. Attackers can submit a token such as a long run of vowels, causing the unguarded onset reversal loop to perform quadratic work and deny service to syllabification components.
- Score
- 6.9 medium
- Published
- 2026-11-13
- Links
- NVD · cve.org · Report wrong data
Matched ports (1)
| Port | Package | Version | Status | Maintainer |
|---|---|---|---|---|
| textproc/py-nltk | py312-nltk | 3.10.0,2 | unaddressed | demon@FreeBSD.org |
Template for a VuXML entry
Check the version numbers before you commit this entry. Some ports share an entry in the CVE database with another port, such as sqlite2 and sqlite3. The version shown here may then be one that never existed for this port.
Ranges per package from the CVE rows that match this port, in pkg notation with the port's epoch and revision, every bound checked with pkg; one range per epoch the port actually had. make newentry in security/vuxml creates the vid.
<vuln vid="FIXME (make newentry)">
<topic>py312-nltk -- FIXME</topic>
<affects>
<package>
<name>py312-nltk</name>
<range><ge>3.6,2</ge><lt>3.10.4,2</lt></range>
</package>
</affects>
<description>
<body xmlns="http://www.w3.org/1999/xhtml">
<p>CVE-2026-126301: NLTK from 3.6 before 3.10.4 contains an algorithmic
complexity vulnerability in LegalitySyllableTokenizer.tokenize that
allows remote attackers to exhaust CPU by supplying long all-vowel
tokens. Attackers can submit a token such as a long run of vowels,
causing the unguarded onset reversal loop to perform quadratic work
and deny service to syllabification components.</p>
</body>
</description>
<references>
<cvename>CVE-2026-126301</cvename>
<url>https://nvd.nist.gov/vuln/detail/CVE-2026-126301</url>
</references>
<dates>
<discovery>2026-11-13</discovery>
<entry>2026-11-13</entry>
</dates>
</vuln>