Vulnerability · Published Aug 25, 2026 · Assigned by VulnCheck

CVE-2026-79674NLTK 3.10.2 Path Traversal via corpus-reader constructors

High 8.2

In plain English

A high-severity security flaw in nltk from nltk. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.4%top 67.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

NLTK versions before 3.10.3 contain a path sandbox bypass vulnerability in corpus-reader constructors that allows attackers to read files outside the intended data root. Attackers can supply arbitrary corpus root paths to LinThesaurusCorpusReader and PanLexLiteCorpusReader constructors to access filesystem content and SQLite databases outside the pathsec sandbox boundary.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	nltk	no fix listed	DEBIAN-CVE-2026-79674
Debian:13	nltk	no fix listed	DEBIAN-CVE-2026-79674
Debian:14	nltk	3.10.3-1	DEBIAN-CVE-2026-79674
PyPI	nltk	3.10.3	GHSA-3gq4-3j92-5w49
PyPI	nltk	3.10.3	PYSEC-2026-3736

Affected products (as reported)

Vendor	Product	Versions
nltk	nltk	0 – before 3.10.3

Weakness: CWE-73 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

References

GitHub Security Advisory (GHSA-3gq4-3j92-5w49) vendor-advisory
VulnCheck Advisory: NLTK 3.10.2 Path Traversal via corpus-reader constructors third-party-advisory