CVE-2019-14751

HIGHNVD 7.57.5—Elevated

7.5

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.

CVSS v3: 7.5
EG Score: 7.5(medium)
EPSS: 87.3%
KEV: Not listed

Published

August 22, 2019

Last Modified

November 21, 2024

References (16)

cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2020-03/msg00054.html
cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2020-04/msg00001.html
cve@mitrehttps://github.com/mssalvatore/CVE-2019-14751_PoC
cve@mitrehttps://github.com/nltk/nltk/blob/3.4.5/ChangeLog
cve@mitrehttps://github.com/nltk/nltk/commit/f59d7ed8df2e0e957f7f247fe218032abdbe9a10
cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QI4IJGLZQ5S7C5LNRNROHAO2P526XE3D/
cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZGZSSEJH7RHH3RBUEVWWYT75QU67J7SE/
cve@mitrehttps://salvatoresecurity.com/zip-slip-in-nltk-cve-2019-14751/
af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00054.html
af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00001.html
af854a3a-2127-422b-91ae-364da2661108https://github.com/mssalvatore/CVE-2019-14751_PoC
af854a3a-2127-422b-91ae-364da2661108https://github.com/nltk/nltk/blob/3.4.5/ChangeLog
af854a3a-2127-422b-91ae-364da2661108https://github.com/nltk/nltk/commit/f59d7ed8df2e0e957f7f247fe218032abdbe9a10
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QI4IJGLZQ5S7C5LNRNROHAO2P526XE3D/
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZGZSSEJH7RHH3RBUEVWWYT75QU67J7SE/

Patch Availability(1)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
ubuntu	python3-nltk (3.1-1ubuntu0.1) @ xenial	2026-05-27	ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)

PyPI(1)

Package	Vulnerable range	Fixed in	Dependents
nltk	2.0.1rc2-git ... 3.4.4 (45 versions)	3.4.5	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-22Path Traversal

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

UbuntuUSN-4106-1MEDIUM
NLTK vulnerability

Data Freshness Timeline

(refreshed 8× in last 7d / 14× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-04 13:10 UTCepss_batch
2026-06-04 13:10 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:14 UTCepss_batch
2026-05-31 00:14 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 15:25 UTCEG score recompute
2026-05-27 15:25 UTCVendor advisory
2026-05-27 13:38 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

GitHub PoCmssalvatore/CVE-2019-14751_PoC
First seen Aug 9, 2019
A Proof of Concept for CVE-2019-14751
Open source ↗

Frequently asked(5)

What is CVE-2019-14751?

CVE-2019-14751 is a high vulnerability published on August 22, 2019. 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.

When was CVE-2019-14751 disclosed?

CVE-2019-14751 was first published in the National Vulnerability Database on August 22, 2019, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2019-14751 actively exploited?

CVE-2019-14751 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 87.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2019-14751?

CVE-2019-14751 has a CVSS v3 base score of 7.5 (NVD).

How do I remediate CVE-2019-14751?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2019-14751, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2019-14751

Explore →

Is Your Infrastructure Affected by CVE-2019-14751?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2019-14751

Published

Last Modified

References (16)

Patch Availability(1)

Affected Packages

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Publicly available exploits

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2019-14751?

Same vendor

Same CWE

CVE-2019-14751

📅 Published

🔄 Last Modified

🔗 References (16)

Patch Availability(1)

Affected Packages

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Publicly available exploits

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2019-14751?

🔗 Related CVEs(same vendor + same CWE)

Same vendor

Same CWE

Published

Last Modified

References (16)

Frequently asked(5)

Related CVEs(same vendor + same CWE)