Nltk CVE-2025-14009

Arbitrary code execution in the NLTK (Natural Language Toolkit) Python library affects all versions, where the downloader's _unzip_iter function in nltk/downloader.py calls zipfile.extractall() with no path validation. Because NLTK treats every downloaded data package as trusted, a malicious zip can drop Python files (e.g. __init__.py) that execute automatically on import, yielding full remote code execution. Publicly available exploit code exists (reported via huntr) and a vendor patch is available; EPSS is modest at 0.57% (68th percentile) and the issue is not listed in CISA KEV.

Arbitrary code execution in NLTK (Natural Language Toolkit, all versions) arises because the downloader's _unzip_iter function in nltk/downloader.py calls zipfile.extractall() with no path validation or content checks, trusting every downloaded data package. A malicious package can drop Python files such as __init__.py that execute automatically on import, yielding remote code execution and full host compromise. Publicly available exploit code exists and a vendor patch is available; EPSS is modest at 0.57% (68th percentile), and there is no public evidence of active exploitation.

Arbitrary code execution in the NLTK Python library affects all versions through its data downloader, which calls zipfile.extractall() in the _unzip_iter function (nltk/downloader.py) without path validation. An attacker who controls the contents of a downloaded data package can plant Python files (e.g., __init__.py) that execute automatically when the package is imported, yielding remote code execution and full host compromise. Publicly available exploit code exists (huntr), though there is no public exploit identified as actively exploited; EPSS is moderate at 0.57% (68th percentile).