NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place symlinks inside the corpus root to access files outside the intended boundary.
History

Mon, 31 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-22
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 24 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 22 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
Description NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place symlinks inside the corpus root to access files outside the intended boundary.
Title NLTK before 3.9.4 Symlink Escape via CorpusReader
First Time appeared Nltk
Nltk nltk
Weaknesses CWE-59
CPEs cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*
Vendors & Products Nltk
Nltk nltk
References
Metrics cvssV3_1

{'score': 6.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-08-22T14:12:44.983Z

Updated: 2026-08-24T19:49:30.565Z

Reserved: 2026-08-04T20:17:18.297Z

Link: CVE-2026-70626

cve-icon Vulnrichment

Updated: 2026-08-24T19:49:06.387Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-22T15:16:21.100

Modified: 2026-08-31T19:09:01.757

Link: CVE-2026-70626

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-22T14:12:44Z

Links: CVE-2026-70626 - Bugzilla