CVE-2026-81727 | High | 7.1 | 2026-08-27 | NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incr_download methods that allows a… |
CVE-2026-81726 | High | 7.0 | 2026-08-27 | NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by using raw file operations on caller-contr… |
CVE-2026-81725 | Low | 3.7 | 2026-08-27 | NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption… |
CVE-2026-81724 | Medium | 5.3 | 2026-08-27 | NLTK before 3.10.3 contains an uncontrolled recursion vulnerability in nltk.featstruct.FeatStructReader that allows unauthenticated attackers to cause a denial… |
CVE-2026-81723 | Low | 3.7 | 2026-08-27 | NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment() that rescans accumulated XML fragments on ev… |
CVE-2026-81722 | High | 7.5 | 2026-08-27 | nltk PorterStemmer in versions <= 3.10.2 (fixed in 3.10.3) contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem(). The _is_co… |
CVE-2026-80206 | Medium | 5.9 | 2026-08-26 | NLTK before 3.10.3 contains a regular expression denial of service (ReDoS) vulnerability in the tgrep module. The _tgrep_node_action function compiles user-sup… |
CVE-2026-80205 | High | 7.5 | 2026-08-26 | NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall() and TokenSearcher.findall() methods that accept user… |
CVE-2026-79676 | Medium | 5.9 | 2026-08-25 | NLTK versions before 3.10.3 contain a path traversal vulnerability in corpus readers that reopen root-derived paths using built-in open() instead of nltk.paths… |
CVE-2026-79675 | Critical | 9.8 | 2026-08-25 | NLTK before 3.10.3 fails to validate JVM options passed through the per-call options parameter in the java() function, allowing attackers to inject dangerous J… |
CVE-2026-79674 | High | 8.2 | 2026-08-25 | NLTK versions before 3.10.3 contain a path sandbox bypass vulnerability in corpus-reader constructors that allows attackers to read files outside the intended… |
CVE-2026-79657 | Critical | 9.8 | 2026-08-25 | NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific… |
CVE-2026-78683 | Critical | 9.6 | 2026-08-25 | NLTK before 3.10.0 (affected versions <=3.9.4) contains an unsafe pickle deserialization vulnerability in the TransitionParser.parse() method (nltk/parse/trans… |
CVE-2026-78682 | High | 7.5 | 2026-08-25 | NLTK before 3.10.3 contains a server-side request forgery vulnerability in nltk.pathsec.urlopen (and callers nltk.data.load, nltk.downloader.Downloader.index/d… |
CVE-2026-78681 | High | 7.5 | 2026-08-25 | NLTK versions before 3.10.3 use xml.etree.ElementTree to parse XML in multiple modules, which honors entity declarations in document DTDs. Attackers can craft… |
CVE-2026-78680 | High | 7.8 | 2026-08-25 | NLTK versions before 3.10.3 fail to use validated absolute paths when invoking the Graphviz dot binary in dependencygraph.dot2img and AlignedSent._repr_svg_, a… |
CVE-2026-70626 | Medium | 6.2 | 2026-08-22 | NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus… |
CVE-2026-66393 | High | 7.5 | 2026-08-22 | NLTK versions before 3.9.4 contain an unbounded recursion vulnerability in JSONTaggedDecoder.decode_obj() that allows attackers to cause denial of service by s… |
CVE-2026-65915 | Medium | 6.5 | 2026-08-22 | NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, m… |
CVE-2026-63312 | High | 7.5 | 2026-08-22 | NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() direc… |
CVE-2026-63311 | Medium | 5.3 | 2026-08-22 | NLTK before 3.10.0 (affected versions <= 3.9.4) contains a server-side request forgery (SSRF) vulnerability in the validate_network_url() function in nltk/path… |
CVE-2026-62388 | High | 7.5 | 2026-08-22 | NLTK versions before 3.10.0 default to ENFORCE=False in pathsec.py, causing all security validation functions to emit warnings instead of raising exceptions. A… |
CVE-2026-62385 | Medium | 5.9 | 2026-08-22 | NLTK versions before 3.10.0 contain a path traversal vulnerability in FramenetCorpusReader and NKJPCorpusReader that allows attackers to parse XML files outsid… |
CVE-2026-62384 | High | 7.5 | 2026-08-22 | NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus… |
CVE-2026-62383 | Medium | 5.5 | 2026-08-22 | nltk versions before 3.10.2 contain a symlink-based arbitrary file read vulnerability in IPIPANCorpusReader methods that bypass nltk.pathsec validation entirel… |
CVE-2026-71514 | Low | 2.5 | 2026-08-22 | NLTK 3.9.4 through 3.10.2 contains a path traversal vulnerability in CrubadanCorpusReader. _load_lang_ngrams joins the corpus root with crubadan_code, the colu… |
CVE-2026-71513 | High | 8.8 | 2026-08-22 | NLTK before 3.10.3 contains a remote code execution vulnerability in AllowlistUnpickler that validates only the pickle module string and not the global name, a… |
CVE-2026-72818 | High | 7.5 | 2026-08-20 | The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORD_RE and applied by TweetTokenizer.tokenize, contains a naked-domain br… |
CVE-2026-12372 | Low | 3.7 | 2026-08-09 | A Server-Side Request Forgery (SSRF) vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The `nltk.pathsec.validate_network_url()`… |
CVE-2026-12261 | Medium | 6.5 | 2026-08-07 | A vulnerability in `nltk.downloader` in nltk/nltk versions <= 3.9.4 allows for cross-package resource and model poisoning. The downloader extracts package arch… |
CVE-2026-12259 | Medium | 5.3 | 2026-08-03 | In nltk version 3.9.4, the `nltk.downloader.Downloader._download_package()` function writes downloaded package bytes to disk and may extract them before enforc… |
CVE-2025-71408 | High | 7.8 | 2026-07-24 | NLTK (Natural Language Toolkit) before version 3.9.3 contains an eval injection vulnerability in the nltk.collocations module that allows an attacker who contr… |
CVE-2026-12252 | High | 7.8 | 2026-07-04 | In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and S… |
CVE-2026-54293 | High | 7.5 | 2026-06-22 | NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Proc… |
CVE-2026-12199 | High | 7.5 | 2026-06-17 | 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 i… |
CVE-2026-33236 | High | 8.1 | 2026-03-20 | NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Proc… |
CVE-2026-33231 | High | 7.5 | 2026-03-20 | NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Proc… |
CVE-2026-33230 | Medium | 6.1 | 2026-03-20 | NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Proc… |
CVE-2026-0846 | High | 7.5 | 2026-03-09 | 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 p… |
CVE-2026-0848 | Critical | 10.0 | 2026-03-05 | NLTK versions <=3.9.2 are vulnerable to arbitrary code execution due to improper input validation in the StanfordSegmenter module. The module dynamically loads… |
CVE-2026-0847 | High | 7.5 | 2026-03-04 | A vulnerability in NLTK versions up to and including 3.9.2 allows arbitrary file read via path traversal in multiple CorpusReader classes, including WordListCo… |
CVE-2025-14009 | High | 8.8 | 2026-02-18 | A critical vulnerability exists in the NLTK downloader component of nltk/nltk, affecting all versions. The _unzip_iter function in nltk/downloader.py uses zipf… |
CVE-2021-3842 | High | 7.5 | 2022-01-04 | nltk is vulnerable to Inefficient Regular Expression Complexity |
CVE-2021-43854 | High | 7.5 | 2021-12-23 | NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Proc… |
CVE-2021-3828 | High | 7.5 | 2021-09-27 | nltk is vulnerable to Inefficient Regular Expression Complexity |
CVE-2019-14751 | High | 7.5 | 2019-08-22 | 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 (… |