CVE-2026-79676 NLTK before 3.10.3 Path Traversal via Symlink Bypass
Attackers can disclose files outside the trusted root via symlinked corpus files in NLTK, affecting applications using its corpus readers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-79676?
CVE-2026-79676 is a high-severity path traversal vulnerability in nltk, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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().
Weakness: CWE-22
Which versions are affected by CVE-2026-79676?
3 open source packages ship an affected version, including nltk. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
nltk PyPI | All versions | 3.10.3 |
nltk PyPI | All versions | 3.10.3 |
nltk PyPI | All versions | 3.10.3 |
Products include Nltk Nltk.
How do I fix CVE-2026-79676?
Upgrade nltk to 3.10.3 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-79676 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-79676 exists.
Other vulnerabilities in nltk
- CVE-2026-0848 Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading
- CVE-2025-14009 Zip Slip Vulnerability in nltk/nltk Leading to Remote Code Execution
- CVE-2026-78683 NLTK before 3.10.0 Remote Code Execution via Unsafe Pickle Deserialization
- CVE-2026-79657 NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization
- CVE-2026-79675 NLTK before 3.10.3 JVM Argument Injection via Per-Call Options
Sources
Also known as DEBIAN-CVE-2026-79676, ECHO-7e2e-a439-e9d3, GHSA-p4rw-rvv2-7xwr, MINI-gpwx-8396-w5v4, PYSEC-2026-3737, UBUNTU-CVE-2026-79676.