Threats tagged 'brew-acronym-cve-2026-79657'

NLTK's current source code allows arbitrary code execution during supposedly safer allowlisted pickle loading due to overly broad module-prefix allowlists. These allowlists trust entire namespaces instead of specific safe globals, enabling crafted pickles to invoke dangerous callables such as ReppTokenizer._execute and numpy.f2py.crackfortran.myeval. This vulnerability affects certain public loaders in NLTK versions before 2.0.0_5 and has a critical CVSS score of 9.3. A patch is available in version 2.0.0_5 that tightens the allowlists to exact (module, qualname) pairs and denies dangerous modules as a backstop. The vulnerability enables remote code execution when loading attacker-controlled tokenizer or model artifacts.