CVE-2026-81726

Name	CVE-2026-81726
Description	NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by using raw file operations on caller-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagger, and maxent parameter APIs when pathsec is enabled.
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	1146873

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)			1146873

Notes

[trixie] - nltk <no-dsa> (Minor issue)
[bookworm] - nltk <postponed> (Minor issue)
https://github.com/nltk/nltk/security/advisories/GHSA-8mgp-746c-j5xp