Nltk
by Nltk
Source repositories
CVEs (24)
| CVE | Vendor / Product | Sev | Risk | CVSS | EPSS | KEV | Published | Description |
|---|---|---|---|---|---|---|---|---|
| CVE-2026-0848 | Cri | 0.65 | 10.0 | 0.01 | Mar 5, 2026 | 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 JAR file, enabling… | ||
| CVE-2024-39705 | Cri | 0.57 | 9.8 | 0.01 | Jun 27, 2024 | NLTK through 3.8.1 allows remote code execution if untrusted packages have pickled Python code, and the integrated data package download functionality is used. This affects, for example, averaged_perceptron_tagger and punkt. | ||
| CVE-2026-12252 | Hig | 0.51 | 7.8 | 0.00 | Jul 4, 2026 | 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 user-controllable… | ||
| CVE-2025-14009 | Hig | 0.50 | 8.8 | 0.01 | Feb 18, 2026 | 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 craft malicious zip… | ||
| CVE-2026-54293 | Hig | 0.49 | 7.5 | 0.01 | Jun 22, 2026 | 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-encoded path separators… | ||
| CVE-2026-33236 | Hig | 0.46 | 8.1 | 0.01 | Mar 20, 2026 | 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` attributes when… | ||
| CVE-2026-12075 | hig | 0.45 | — | — | Jul 31, 2026 | ### Summary `nltk.pathsec` provides an SSRF filter that NLTK documents as a security control, blocking loopback, private, link-local, and multicast ranges (including obfuscated forms) and recommending strict `ENFORCE` mode for security-sensitive environments. The filter is… | ||
| CVE-2026-12061 | hig | 0.45 | — | — | Jul 31, 2026 | ### Summary `ReviewsCorpusReader` extracts feature annotations of the form *label* followed by a bracketed signed digit (e.g. a label then `[+2]`) from each review line, using the module-level `FEATURES` regex. The feature-label sub-pattern is unbounded — an optional greedy… | ||
| CVE-2026-12074 | hig | 0.45 | — | — | Jul 31, 2026 | ### Summary `FramenetCorpusReader.frame(name)` interpolates a caller-supplied frame name into an XML file path that is read with the builtin `open()`, bypassing `CorpusReader.open()` and the `nltk.pathsec` sandbox — including strict `ENFORCE=True` mode. A `../` sequence in the… | ||
| CVE-2025-71408 | Hig | 0.44 | 7.8 | 0.00 | Jul 24, 2026 | NLTK (Natural Language Toolkit) before version 3.9.3 contains an eval injection vulnerability in the nltk.collocations module that allows an attacker who controls command-line arguments to execute arbitrary Python code. When collocations.py is invoked directly, the __main__… | ||
| CVE-2026-12243 | Hig | 0.42 | 7.5 | 0.01 | Jun 30, 2026 | NLTK version 3.9.4 is vulnerable to a path traversal attack due to an incomplete fix for GitHub Issue #3504. The `_UNSAFE_NO_PROTOCOL_RE` regex in `nltk/data.py` checks for literal `../` sequences but fails to account for percent-encoded traversal sequences such as `..%2f`. The… | ||
| CVE-2026-12199 | Hig | 0.42 | 7.5 | 0.00 | Jun 17, 2026 | 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 request… | ||
| CVE-2026-33231 | Hig | 0.42 | 7.5 | 0.01 | Mar 20, 2026 | 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 of the local WordNet… | ||
| CVE-2026-0846 | Hig | 0.42 | 7.5 | 0.00 | Mar 9, 2026 | 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 attackers to access… | ||
| CVE-2026-0847 | Hig | 0.42 | 7.5 | 0.01 | Mar 4, 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… | ||
| CVE-2021-3842 | Hig | 0.42 | 7.5 | 0.01 | Jan 4, 2022 | nltk is vulnerable to Inefficient Regular Expression Complexity | ||
| CVE-2021-43854 | Hig | 0.42 | 7.5 | 0.03 | Dec 23, 2021 | 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) attacks. The… | ||
| CVE-2021-3828 | Hig | 0.42 | 7.5 | 0.02 | Sep 27, 2021 | nltk is vulnerable to Inefficient Regular Expression Complexity | ||
| CVE-2019-14751 | Hig | 0.42 | 7.5 | 0.06 | Aug 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. | ||
| CVE-2026-12072 | hig | 0.38 | — | — | Jul 31, 2026 | ### Summary A path-traversal vulnerability in `NKJPCorpusReader` allows an attacker who can influence the `fileids` argument of its public read methods (`header`, `raw`, `words`, `sents`, `tagged_words`) to read files outside the corpus root. The reader builds the… |
- risk 0.65cvss 10.0epss 0.01
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 JAR file, enabling…
- risk 0.57cvss 9.8epss 0.01
NLTK through 3.8.1 allows remote code execution if untrusted packages have pickled Python code, and the integrated data package download functionality is used. This affects, for example, averaged_perceptron_tagger and punkt.
- risk 0.51cvss 7.8epss 0.00
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 user-controllable…
- risk 0.50cvss 8.8epss 0.01
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 craft malicious zip…
- risk 0.49cvss 7.5epss 0.01
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-encoded path separators…
- risk 0.46cvss 8.1epss 0.01
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` attributes when…
- risk 0.45cvss —epss —
### Summary `nltk.pathsec` provides an SSRF filter that NLTK documents as a security control, blocking loopback, private, link-local, and multicast ranges (including obfuscated forms) and recommending strict `ENFORCE` mode for security-sensitive environments. The filter is…
- risk 0.45cvss —epss —
### Summary `ReviewsCorpusReader` extracts feature annotations of the form *label* followed by a bracketed signed digit (e.g. a label then `[+2]`) from each review line, using the module-level `FEATURES` regex. The feature-label sub-pattern is unbounded — an optional greedy…
- risk 0.45cvss —epss —
### Summary `FramenetCorpusReader.frame(name)` interpolates a caller-supplied frame name into an XML file path that is read with the builtin `open()`, bypassing `CorpusReader.open()` and the `nltk.pathsec` sandbox — including strict `ENFORCE=True` mode. A `../` sequence in the…
- risk 0.44cvss 7.8epss 0.00
NLTK (Natural Language Toolkit) before version 3.9.3 contains an eval injection vulnerability in the nltk.collocations module that allows an attacker who controls command-line arguments to execute arbitrary Python code. When collocations.py is invoked directly, the __main__…
- risk 0.42cvss 7.5epss 0.01
NLTK version 3.9.4 is vulnerable to a path traversal attack due to an incomplete fix for GitHub Issue #3504. The `_UNSAFE_NO_PROTOCOL_RE` regex in `nltk/data.py` checks for literal `../` sequences but fails to account for percent-encoded traversal sequences such as `..%2f`. The…
- risk 0.42cvss 7.5epss 0.00
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 request…
- risk 0.42cvss 7.5epss 0.01
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 of the local WordNet…
- risk 0.42cvss 7.5epss 0.00
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 attackers to access…
- risk 0.42cvss 7.5epss 0.01
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…
- risk 0.42cvss 7.5epss 0.01
nltk is vulnerable to Inefficient Regular Expression Complexity
- risk 0.42cvss 7.5epss 0.03
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) attacks. The…
- risk 0.42cvss 7.5epss 0.02
nltk is vulnerable to Inefficient Regular Expression Complexity
- risk 0.42cvss 7.5epss 0.06
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.
- risk 0.38cvss —epss —
### Summary A path-traversal vulnerability in `NKJPCorpusReader` allows an attacker who can influence the `fileids` argument of its public read methods (`header`, `raw`, `words`, `sents`, `tagged_words`) to read files outside the corpus root. The reader builds the…
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