Vendor
nltk
55 known vulnerabilities.
Products
55 results · Feed
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Medium 5.3
Improper Access Control in nltk/nltk
A vulnerability in `nltk.downloader` in nltk/nltk versions <= 3.9.4 allows for cross-package resource and model poisoning. The downloader extracts package archives into shared namespaces such as `corpora/` and `taggers/` instead of package-isolated roots, and…
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Medium 5.3
Improper Input Validation in nltk/nltk
In nltk version 3.9.4, the `nltk.downloader.Downloader._download_package()` function writes downloaded package bytes to disk and may extract them before enforcing SHA-256 or MD5 checksum validation. This allows an attacker to tamper with the package response …
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High 7.8
Untrusted JAR Code Execution in Multiple Stanford Interface Classes in nltk/nltk
In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and StanfordNeuralDependencyParser) are vulnerable to untrusted JAR code execution. These classes accept …
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High 7.5
NLTK: URL-Encoded Path Traversal in nltk.data.load() Allows Arbitrary Local File Read
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Prior to 3.10.0-rc1, nltk.data.load() in NLTK is vulnerable to path traversal via URL-encode…
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High 7.5
Unauthenticated Denial of Service in nltk.app.wordnet_app
A vulnerability in `nltk.app.wordnet_app` up to version 3.9.3 allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when started in its default mode. The server listens on all interfaces and processes a specific unauthenticated GET r…
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High 8.1
NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, the NLTK downloader does not validate the `subdir` and `id` att…
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High 7.5
NLTK has unauthenticated remote shutdown in nltk.app.wordnet_app
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, `nltk.app.wordnet_app` allows unauthenticated remote shutdown o…
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Medium 6.1
nltk Vulnerable to Cross-site Scripting
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, `nltk.app.wordnet_app` contains a reflected cross-site scriptin…
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High 8.6
Arbitrary File Read via Absolute Path Input in nltk.util.filestring()
A vulnerability in the `filestring()` function of the `nltk.util` module in nltk version 3.9.2 allows arbitrary file read due to improper validation of input paths. The function directly opens files specified by user input without sanitization, enabling attac…
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Critical 10.0CVE-2026-0848 Public exploit
Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading
NLTK versions <=3.9.2 are vulnerable to arbitrary code execution due to improper input validation in the StanfordSegmenter module. The module dynamically loads external Java .jar files without verification or sandboxing. An attacker can supply or replace the …
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High 8.6CVE-2026-0847 Public exploit
Path Traversal in nltk/nltk
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 sanitiz…
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Critical 10.0
Zip Slip Vulnerability in nltk/nltk Leading to Remote Code Execution
A critical vulnerability exists in the NLTK downloader component of nltk/nltk, affecting all versions. The _unzip_iter function in nltk/downloader.py uses zipfile.extractall() without performing path validation or security checks. This allows attackers to cra…
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High 7.5
Inefficient Regular Expression Complexity in nltk/nltk
nltk is vulnerable to Inefficient Regular Expression Complexity
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High 7.5
Inefficient Regular Expression Complexity in nltk
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Versions prior to 3.6.5 are vulnerable to regular expression denial of service (ReDoS) attac…
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High 7.5
Inefficient Regular Expression Complexity in nltk/nltk
nltk is vulnerable to Inefficient Regular Expression Complexity