CVE-2026-0847
March 04, 2026
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
nltk (CONDA):
Affected version(s) >=2.0.3 <3.9.3Fix Suggestion:
Update to version 3.9.3https://github.com/nltk/nltk.git (GITHUB):
Affected version(s) =v3.9.2 <3.9.3Fix Suggestion:
Update to version 3.9.3nltk (PYTHON):
Affected version(s) >=0.8 <3.9.3Fix Suggestion:
Update to version 3.9.3Related ResourcesĀ (1)
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Contact UsCVSS v4
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
LOW
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
LOW
Weakness Type (CWE)
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
EPSS
Base Score:
0.19