CVE-2026-109956

Name	CVE-2026-109956
Description	NLTK through 3.10.3 contains a path traversal vulnerability in WekaClassifier that allows attackers to bypass nltk.pathsec containment by supplying unvalidated model paths. Attackers controlling the model_filename or model argument can make the weka JVM write files via -d or probe files via -l outside allowed data roots.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1150904

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
nltk (PTS)	bookworm	3.8-1	vulnerable
	trixie	3.9.1-2	vulnerable
	forky, sid	3.10.3-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
nltk	source	(unstable)	(unfixed)			1150904

Notes

https://github.com/nltk/nltk/security/advisories/GHSA-j456-xh4h-cpf2
https://github.com/nltk/nltk/pull/3863
https://github.com/nltk/nltk/commit/6a17606293fe9d3ea1006f99dd3fed2e2b25d519