CVE-2026-70626

NLTK before 3.9.4 Symlink Escape via CorpusReader

Published Aug 22, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-r6gq-whwq-mvg9 NLTK: Symlink escape in CorpusReader allows arbitrary local file read outside the corpus root
History
Type Values Removed Values Added
Metrics ssvc

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

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 24, 2026, 7:49 PM
Reserved
Aug 4, 2026, 8:17 PM
Status
Analyzed
Published
Aug 22, 2026, 3:16 PM
Modified
Oct 14, 2026, 1:10 PM
Severity
Moderate
Public date
Aug 22, 2026, 2:12 PM