CVE-2026-126300
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.
- 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>3.2.5,2</ge><lt>3.10.4,2</lt></range>
</package>
</affects>
<description>
<body xmlns="http://www.w3.org/1999/xhtml">
<p>CVE-2026-126300: 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.</p>
</body>
</description>
<references>
<cvename>CVE-2026-126300</cvename>
<url>https://nvd.nist.gov/vuln/detail/CVE-2026-126300</url>
</references>
<dates>
<discovery>2026-11-13</discovery>
<entry>2026-11-13</entry>
</dates>
</vuln>