CVE-2026-62384: NLTK FramenetCorpusReader Symlink Sandbox Bypass before 3.10.2
NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus root. Attackers can place symlinks with names containing no path separators inside the corpus subdirectory, which pass the path validation guard and are resolved to files outside the intended corpus root when accessed via framebyname(), lufile(), or doc() methods.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
NLTK FramenetCorpusReaderto a version that resolves this vulnerability.Fixed in 3.10.2 - Compensating control
If you cannot upgrade immediately, prevent untrusted users from having the ability to place symlinks (or symlink-like files) with names lacking path separators inside the corpus subdirectory.
Event History
Frequently Asked Questions
What conditions are required for exploitation?
An attacker must be able to place a symlink inside the FrameNet corpus subdirectory. The symlink name must contain no path separators, and exploitation occurs when the application accesses it through frame_by_name(), _lu_file(), or doc().
What data can be exposed?
The flaw allows reading arbitrary XML files located outside the intended corpus root when a permitted symlink resolves to those files. The issue affects confidentiality; no integrity or availability impact is specified.
Which versions should be remediated?
NLTK FramenetCorpusReader versions before 3.10.2 are affected. Update to version 3.10.2 or later.