nltk versions before 3.10.2 contain a symlink-based arbitrary file read vulnerability in IPIPANCorpusReader methods that bypass nltk.pathsec validation entirely. Attackers can place a symlink in the corpus root directory and read arbitrary files accessible to the process by calling channels(), domains(), categories(), or fileids() methods with the symlink filename.
https://www.vulncheck.com/advisories/nltk-ipipancorpusreader-symlink-arbitrary-file-read
https://github.com/nltk/nltk/security/advisories/GHSA-3hhw-38pf-pxj6
Published: 2026-08-22
Updated: 2026-08-22
Base Score: 4.6
Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:N/A:N
Severity: Medium
Base Score: 5.5
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Severity: Medium
Base Score: 6.8
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Severity: Medium