CVE-2026-126303
NLTK before 3.10.4 contains an uncontrolled resource consumption vulnerability in SteppingRecursiveDescentParser.parse() that lacks any max_time deadline or step limit. Attackers influencing the grammar can supply an ambiguous self-embedding grammar and short token input to force unbounded top-down search, pinning CPU cores and exhausting worker pools.
- Score
- 8.7 high
- 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><lt>3.10.4,2</lt></range>
</package>
</affects>
<description>
<body xmlns="http://www.w3.org/1999/xhtml">
<p>CVE-2026-126303: NLTK before 3.10.4 contains an uncontrolled resource
consumption vulnerability in SteppingRecursiveDescentParser.parse()
that lacks any max_time deadline or step limit. Attackers
influencing the grammar can supply an ambiguous self-embedding
grammar and short token input to force unbounded top-down search,
pinning CPU cores and exhausting worker pools.</p>
</body>
</description>
<references>
<cvename>CVE-2026-126303</cvename>
<url>https://nvd.nist.gov/vuln/detail/CVE-2026-126303</url>
</references>
<dates>
<discovery>2026-11-13</discovery>
<entry>2026-11-13</entry>
</dates>
</vuln>