What’s Vulnerable › Vulnerabilities

CVE-2026-79676: NLTK before 3.10.3 Path Traversal via Symlink Bypass

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-08-25 · updated 2026-08-31
• Weakness: CWE-22

Description

NLTK versions before 3.10.3 contain a path traversal vulnerability in corpus readers that reopen root-derived paths using built-in open() instead of nltk.pathsec.open(), allowing symlinks to escape trusted roots. Attackers who stage symlinked corpus files under a trusted data root can disclose outside-root content through normal corpus reader methods like channels(), domains(), and synonyms().

Affected products

• nltk: before 3.10.3 — fixed in 3.10.3

How to fix

Upgrade to a fixed version: nltk 3.10.3. Check the vendor advisory for mitigations.

References

• https://github.com/nltk/nltk/security/advisories/GHSA-p4rw-rvv2-7xwr
• https://www.vulncheck.com/advisories/nltk-before-path-traversal-via-symlink-bypass
• https://github.com/nltk/nltk/security/advisories/GHSA-p4rw-rvv2-7xwr

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