Path Traversal in NLTK via FramenetCorpusReader and NKJPCorpusReader

Executive Summary

CVE-2026-62385 is a path traversal vulnerability in NLTK versions before 3.10.0 affecting FramenetCorpusReader and NKJPCorpusReader. Attackers can exploit unsafe selectors or poisoned index state to parse XML files outside the corpus root directory by using methods like frame_by_name, doc, lu, and header with crafted parameters.

Useful 0 Not Useful 0

Detection Guidance

Check NLTK version with pip show nltk. If version is below 3.10.0, the system is vulnerable. Review application logs for suspicious XML file access attempts or errors related to FramenetCorpusReader or NKJPCorpusReader methods like frame_by_name, doc, lu, or header.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability allows attackers to read arbitrary XML files accessible to the application. If exploited, it could lead to unauthorized access to sensitive data stored in XML files outside the intended corpus directory, potentially exposing confidential information.

Useful 0 Not Useful 0

Compliance Impact

This vulnerability could lead to unauthorized data access, violating GDPR and HIPAA requirements for data protection and confidentiality. Organizations using affected NLTK versions may face compliance violations if sensitive data is exposed through this path traversal flaw.

Useful 0 Not Useful 0

Mitigation Strategies

Upgrade NLTK to version 3.10.0 or later immediately. If upgrading is not possible, restrict access to the affected NLTK readers or disable their use in applications processing untrusted input. Monitor for unauthorized file access attempts.

Useful 0 Not Useful 0