EUVD-2026-52226

NLTK: Missing Post-Download Integrity Verification Allows Malicious Package Injection...

CVE-2026-12372

A flaw was found in NLTK. A Server-Side Request Forgery SSRF vulnerability allows an attacker to influence a URL passed to NLTK's network-loading helpers. This occurs because the nltk.pathsec.validatenetworkurl function fails to properly identify and reject IP addresses within the RFC 6598 shared...

Linux Distros Unpatched Vulnerability : CVE-2026-12261

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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...

PYSEC-2026-3582 Natural Language Toolkit (NLTK): ReDoS in NLTK ReviewsCorpusReader FEATURES regex

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 run of word-plus-whitespace groups...

PYSEC-2026-3581 Natural Language Toolkit (NLTK): Path Traversal in NKJPCorpusReader leads to Arbitrary File Read and bypasses the nltk.pathsec sandbox (ENFORCE=True)

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, taggedwords to read files outside the corpus root. The reader builds the file path with no containment check and opens it with...

CVE-2026-12259

In nltk version 3.9.4, the nltk.downloader.Downloader.downloadpackage 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 body for info.url through a compromised...

CVE-2026-12259 Improper Input Validation in nltk/nltk

In nltk version 3.9.4, the nltk.downloader.Downloader.downloadpackage 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 body for info.url through a compromised...

CVE-2026-12259

In nltk version 3.9.4, the nltk.downloader.Downloader.downloadpackage 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 body for info.url through a compromised...

Natural Language Toolkit (NLTK): ReDoS in NLTK ReviewsCorpusReader FEATURES regex

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 run of word-plus-whitespace groups...

SUSE CVE-2025-71408

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 block passes command-line...

Linux Distros Unpatched Vulnerability : CVE-2025-71408

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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...

EUVD-2025-210509

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 block passes command-line...

Eval Injection

Overview nltk is a Natural Language Toolkit NLTK is a Python package for natural language processing. Affected versions of this package are vulnerable to Eval Injection via the main process in collocations.py when command-line arguments are passed directly to the eval function without proper...

DEBIAN-CVE-2025-71408

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 block passes command-line...

CVE-2025-71408

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 block passes command-line...

CVE-2025-71408

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 block passes command-line...

UBUNTU-CVE-2025-71408

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 block passes command-line...

CVE-2025-71408 NLTK < 3.9.3 Eval Injection via collocations.py Command-Line Arguments

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 block passes command-line...

CVE-2025-71408 NLTK < 3.9.3 Eval Injection via collocations.py Command-Line Arguments

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 block passes command-line...

CVE-2025-71408

The CVE-2025-71408 issue affects NLTK up to version 3.9.2 (pre-3.9.3). The vulnerability lies in nltk.collocations’ main path, where command‑line arguments are passed directly to eval() to form BigramAssocMeasures suffixes without a allowlist or sanitization, enabling an attacker who can control ...