CVE-2026-79657NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization

Description

NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and numpy.f2py.crackfortran.myeval through pickle REDUCE to execute arbitrary commands during model or tokenizer artifact loading.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• GitHub Security Advisory (GHSA-x99w-6fgc-pmfw) vendor-advisoryExploitVendor Advisory
• VulnCheck Advisory: NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization third-party-advisoryThird Party Advisory