NLTK Downloader before 3.4.5 is vulnerable to a directory traversal, allowing attackers…
Priority MEDIUM 41CWE-22Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and GitHub.
Summary
NLTK Downloader before 3.4.5 is vulnerable to a directory traversal, allowing attackers to write arbitrary files via a ../ (dot dot slash) in an NLTK package (ZIP archive) that is mishandled during extraction.
Why it matters now
EPSS 0.05674 93rd percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Fixed nltk (PyPI): 3.4.5
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | nltk (PyPI) | before 3.4.5 | 3.4.5 | Patch available | GHSA-mr7p-25v2-35wr |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- nltk (PyPI) Vendor— Affected before 3.4.5 Fixed in 3.4.5 Patch available GHSA-mr7p-25v2-35wr
Remediation
- Fix · GHSA-mr7p-25v2-35wr nltk (PyPI) Fixed in 3.4.5 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2019-14751
- 2026-10-03 Alias added: GHSA-mr7p-25v2-35wr
References
Exploit 2
Advisory 6
Other 6
- https://github.com/nltk/nltk/blob/3.4.5/ChangeLog
- https://github.com/nltk/nltk
- https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2019-106.yaml
- https://lists.fedoraproject.org/archives/list/[email protected]/message/QI4IJGLZQ5S7C5LNRNROHAO2P526XE3D
- https://lists.fedoraproject.org/archives/list/[email protected]/message/ZGZSSEJH7RHH3RBUEVWWYT75QU67J7SE
- https://salvatoresecurity.com/zip-slip-in-nltk-cve-2019-14751
More Nltk vulnerabilities
- TI-2026-00629 Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading CVSS 3.0CRITICAL 10.0
- TI-2025-12800 Zip Slip Vulnerability in nltk/nltk Leading to Remote Code Execution CVSS 3.0CRITICAL 10.0
- TI-2026-55173 NLTK before 3.10.3 JVM Argument Injection via Per-Call Options CVSS 4.0CRITICAL 9.3
- TI-2026-55155 NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization CVSS 4.0CRITICAL 9.3
- TI-2026-56370 nltk PorterStemmer before 3.10.3 Quadratic-time DoS CVSS 4.0HIGH 8.7
- TI-2026-55172 NLTK 3.10.2 Path Traversal via corpus-reader constructors CVSS 4.0HIGH 8.8
Sources
- CVE-2019-14751 · CVE Program
- CVE-2019-14751 · NVD
- FIRST EPSS
- GHSA-mr7p-25v2-35wr · GitHub Advisory Database · CC BY 4.0
- CVE-2019-14751 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences