Path traversal in Natural Language Toolkit - CVE-2026-54293
Published: August 7, 2026
Vulnerability identifier: #VU141246
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-54293
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to path traversal in nltk.data.load() and related path handling in nltk/data.py when processing attacker-controlled nltk: resource URLs containing URL-encoded path separators or traversal segments. A remote attacker can supply a specially crafted resource identifier to disclose sensitive information.
The issue is caused by a decode-after-check flaw in which unsafe-path regex checks are performed before url2pathname() decodes percent-encoded sequences.
Affected software
Natural Language Toolkit
How to mitigate CVE-2026-54293
Install security update from vendor's website.
Natural Language Toolkit - update to 3.10.0