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-2026-81723

NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView.readxmlfragment that rescans accumulated XML fragments on every 1 KiB block read. Attackers can provide malformed XML corpus files to cause severe CPU consumption and denial of service through affected...

CVE-2019-14751_PoC

CVE-2019-14751PoC Una Proof of Concept per CVE-2019-14751 Descrizione della vulnerabilità NLTK Downloader prima della versione 3.5 è vulnerabile a un directory traversal, che consente agli attaccanti di scrivere file arbitrari tramite un ../ dot dot slash in un pacchetto NLTK archivio ZIP che vie...

CVE-2026-81727

NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incrdownload methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader...

CVE-2026-81727 NLTK before 3.10.3 Hardlink File Overwrite via downloader

NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incrdownload methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader...

EUVD-2026-67077

NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incrdownload methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader...

CVE-2026-81727

NLTK versions before 3.10.3 are affected by a filesystem containment bypass in the Downloader.download and Downloader.incr_download methods. An attacker with write access to a shared downloader directory can create hardlinks pointing to files outside the install root, which are then overwritten d...

CVE-2026-81727 NLTK before 3.10.3 Hardlink File Overwrite via downloader

NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incrdownload methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader...

CVE-2026-81726

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-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagge...

EUVD-2026-67076

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-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagge...

EUVD-2026-67075

NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption by supplying malformed TEI blocks with many unmatched opening tags. Attackers can exploit lazy regex patterns in the readblock method...

CVE-2026-81725 NLTK before 3.10.3 Regular Expression Denial of Service via Pl196xCorpusReader

NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption by supplying malformed TEI blocks with many unmatched opening tags. Attackers can exploit lazy regex patterns in the readblock method...

CVE-2026-81726 NLTK through 3.10.3 Path Traversal via Model-Artifact APIs

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-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagge...

CVE-2026-81726

NLTK through 3.10.3 contains a path traversal vulnerability in its model-artifact APIs. The root cause is that TransitionParser, AveragedPerceptron, PerceptronTagger, and maxent parameter APIs bypass pathsec enforcement by performing raw file operations on caller-controlled paths, allowing attack...

CVE-2026-81726 NLTK through 3.10.3 Path Traversal via Model-Artifact APIs

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-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagge...

CVE-2026-81725

NLTK before 3.10.3 contains a Regular Expression Denial of Service vulnerability in the Pl196xCorpusReader component. The root cause lies in lazy regex patterns within the read_block method, which can be triggered by supplying malformed TEI blocks containing many unmatched opening tags. Attackers...

CVE-2026-81725 NLTK before 3.10.3 Regular Expression Denial of Service via Pl196xCorpusReader

NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption by supplying malformed TEI blocks with many unmatched opening tags. Attackers can exploit lazy regex patterns in the readblock method...

CVE-2026-81725

NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption by supplying malformed TEI blocks with many unmatched opening tags. Attackers can exploit lazy regex patterns in the readblock method...

EUVD-2026-67074

NLTK before 3.10.3 contains an uncontrolled recursion vulnerability in nltk.featstruct.FeatStructReader that allows unauthenticated attackers to cause a denial of service by supplying deeply nested feature-structure input. Attackers can craft trivial payloads with nested brackets that exceed...

CVE-2026-81724

NLTK before 3.10.3 contains an uncontrolled recursion vulnerability in nltk.featstruct.FeatStructReader . Unauthenticated, remote attackers can supply deeply nested feature-structure input—trivially crafted with nested brackets—that exceeds Python's recursion limit and raises an unhandled Recursi...