CVE-2026-70626CWE-59

CVE-2026-70626

Medium · published August 22, 2026

CVSS v3.1
6.2
EPSS
0%
Percentile
9.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.2 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
8.6 · 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
EPSS
0.00200 · 9.3th percentile
Weakness
CWE-59 · Improper Link Resolution Before File Access ('Link Following')
Published
2026-08-22T19:16Z
Affected products (1)
ProductVersionsFixed in
nltk/nltk< 3.9.43.9.4
References (3)
https://github.com/nltk/nltk/security/advisories/GHSA-r6gq-whwq-mvg9 · [email protected]https://www.vulncheck.com/advisories/nltk-before-symlink-escape-via-corpusreader · [email protected]https://github.com/nltk/nltk/security/advisories/GHSA-r6gq-whwq-mvg9 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 22 AUG 14:12Z
    NLTK before 3.9.4 Symlink Escape via CorpusReader
    cvelistv5