Inefficient Algorithmic Complexity

Overview nltk is a Natural Language Toolkit NLTK is a Python package for natural language processing. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity through the XMLCorpusView.readxmlfragment function in nltk/corpus/reader/xmldocs.py. An attacker can exhaust...

CVE-2026-81722 nltk PorterStemmer before 3.10.3 Quadratic-time DoS

nltk PorterStemmer in versions = 3.10.2 fixed in 3.10.3 contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem. The isconsonant helper walks backward over the entire run of trailing 'y' characters on every call, and measure invokes it for each stem position, causin...

CVE-2026-81722 nltk PorterStemmer before 3.10.3 Quadratic-time DoS

nltk PorterStemmer in versions = 3.10.2 fixed in 3.10.3 contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem. The isconsonant helper walks backward over the entire run of trailing 'y' characters on every call, and measure invokes it for each stem position, causin...

CVE-2026-81722

nltk PorterStemmer in versions ≤ 3.10.2 is vulnerable to an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem(). The root cause is that the _is_consonant() helper walks backward over the entire run of trailing 'y' characters on every call, and _measure() invokes it for ea...

CVE-2026-81722

nltk PorterStemmer in versions = 3.10.2 fixed in 3.10.3 contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem. The isconsonant helper walks backward over the entire run of trailing 'y' characters on every call, and measure invokes it for each stem position, causin...

CVE-2026-81722

nltk PorterStemmer in versions = 3.10.2 fixed in 3.10.3 contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem. The isconsonant helper walks backward over the entire run of trailing 'y' characters on every call, and measure invokes it for each stem position, causin...

CVE-2026-81722 nltk PorterStemmer before 3.10.3 Quadratic-time DoS

nltk PorterStemmer in versions = 3.10.2 fixed in 3.10.3 contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem. The isconsonant helper walks backward over the entire run of trailing 'y' characters on every call, and measure invokes it for each stem position, causin...

Inefficient Algorithmic Complexity

Overview nltk is a Natural Language Toolkit NLTK is a Python package for natural language processing. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity via the PorterStemmer.stem path in nltk/stem/porter.py. An attacker can pin a CPU core by supplying a single...

CVE-2026-80206

A flaw was found in NLTK, specifically within its tgrep module. This vulnerability, known as Regular Expression Denial of Service ReDoS, allows a remote attacker to provide specially crafted regular expressions. When processed, these expressions can cause indefinite CPU saturation, leading to a...

CVE-2026-79676

A flaw was found in NLTK. This path traversal vulnerability allows attackers to bypass security measures by using symbolic links within trusted data roots. By staging specially crafted symlinked corpus files, an attacker can disclose sensitive information from outside the intended data directorie...

CVE-2026-80205

A flaw was found in NLTK. A remote attacker can exploit a regular expression denial of service ReDoS vulnerability in the Text.findall and TokenSearcher.findall methods. These methods accept user-supplied regular expressions without validation, allowing an attacker to provide crafted patterns tha...

CVE-2026-79674

A flaw was found in NLTK. A path traversal vulnerability in corpus-reader constructors allows a remote attacker to bypass the intended data root sandbox. By supplying arbitrary corpus root paths to LinThesaurusCorpusReader and PanLexLiteCorpusReader constructors, an attacker can read files and...

CVE-2026-62384

A flaw was found in NLTK. The FramenetCorpusReader component is vulnerable to a symlink-based sandbox bypass. An attacker can exploit this by placing specially crafted symbolic links within a corpus subdirectory. These symlinks bypass path validation, allowing the attacker to read arbitrary XML...

CVE-2026-65915

A flaw was found in NLTK. A logic bug in the FileSystemPathPointer.open function allows the sandbox validation check to be bypassed. A remote attacker can exploit this by providing specially crafted file:// Uniform Resource Locators URLs to nltk.data.load. This enables the attacker to read...

CVE-2026-63311

A flaw was found in NLTK. This server-side request forgery SSRF vulnerability allows an attacker to bypass network access restrictions. By triggering DNS resolution failures or using DNS rebinding, an attacker can cause the validatenetworkurl function to incorrectly validate URLs. This enables...

Linux Distros Unpatched Vulnerability : CVE-2026-81727

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incrdownload methods that allows...

Linux Distros Unpatched Vulnerability : CVE-2026-81722

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - nltk PorterStemmer in versions = 3.10.2 fixed in 3.10.3 contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem. The isconsonant...

Linux Distros Unpatched Vulnerability : CVE-2026-81726

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by using raw file operations on...

Linux Distros Unpatched Vulnerability : CVE-2026-81725

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption ...

Linux Distros Unpatched Vulnerability : CVE-2026-81724

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - NLTK before 3.10.3 contains an uncontrolled recursion vulnerability in nltk.featstruct.FeatStructReader that allows unauthenticated attackers to cause a denial ...