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Vulnerability · Published Mar 4, 2026 · Assigned by @huntr_ai

CVE-2026-0847Path Traversal in nltk/nltk

High 7.5

In plain English

A high-severity path traversal in nltk/nltk from nltk. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 63% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)1.0%top 37.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack tooling1Public PoC

Official description

A vulnerability in NLTK versions up to and including 3.9.2 allows arbitrary file read via path traversal in multiple CorpusReader classes, including WordListCorpusReader, TaggedCorpusReader, and BracketParseCorpusReader. These classes fail to properly sanitize or validate file paths, enabling attackers to traverse directories and access sensitive files on the server. This issue is particularly critical in scenarios where user-controlled file inputs are processed, such as in machine learning APIs, chatbots, or NLP pipelines. Exploitation of this vulnerability can lead to unauthorized access to sensitive files, including system files, SSH private keys, and API tokens, and may potentially escalate to remote code execution when combined with other vulnerabilities.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12nltkno fix listedDEBIAN-CVE-2026-0847
Debian:13nltkno fix listedDEBIAN-CVE-2026-0847
Debian:14nltk3.9.3-1DEBIAN-CVE-2026-0847
PyPInltk3.9.3PYSEC-2026-98
PyPInltk3.9.3GHSA-68j8-pq59-fqgm
Ubuntu:25.10nltkno fix listedUBUNTU-CVE-2026-0847
Ubuntu:26.10nltkno fix listedUBUNTU-CVE-2026-0847

Affected products (as reported)

VendorProductVersions
nltk nltk/nltk unspecified – through latest

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References