CVE-2026-70626

high

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.

References

https://www.vulncheck.com/advisories/nltk-before-symlink-escape-via-corpusreader

https://github.com/nltk/nltk/security/advisories/GHSA-r6gq-whwq-mvg9

Details

Source: Mitre, NVD

Published: 2026-08-22

Updated: 2026-08-22

Risk Information

CVSS v2

Base Score: 4.9

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 6.2

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Severity: Medium

CVSS v4

Base 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

Severity: High

EPSS

EPSS: 0.00187