Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-70626

CVE-2026-70626HIGH

NLTK before 3.9.4 Symlink Escape via CorpusReader

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   L   L   N   N   N   H   H   H    8.6   .0020    8.9     —

AFFECTED
  Product  Versions     Fixed
  nltk     unspecified  3.9.4

TIMELINE
  Aug 4   Reserved by VulnCheck
  Aug 22  Published (CNA: VulnCheck)
  Aug 31  EXPLOIT PUBLISHED — CVE-2026-70626 (nltk). Public exploit reference added.

CWE-59 · CNA: VulnCheck · CVSS v4.0 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
August 4, 2026	Reserved	Reserved by VulnCheck
August 22, 2026	Published	Published (CNA: VulnCheck)
August 31, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-70626 (nltk). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
nltk	nltk	—	—	3.9.4

Weaknesses

CWE-59

References (2)

https://github.com/nltk/nltk/security/advisories/GHSA-r6gq-whwq-mvg9 [Exploit, Vendor Advisory]
https://www.vulncheck.com/advisories/nltk-before-symlink-escape-via-corpusreader [Vendor Advisory]

Authoritative record: CVE-2026-70626 at cve.org

Vendors: nltk

Weaknesses: CWE-59

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-70626 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.