CVE-2025-71408

Description

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 arguments directly to eval() as suffixes of BigramAssocMeasures without allowlist validation or sanitization, enabling an attacker to supply a Python expression that escapes the intended attribute lookup and executes arbitrary code including OS commands via the os module.

Weakness classification

• disclosure@vulncheck.com: CWE-95

Primary references

• disclosure@vulncheck.com — Exploit, Press/Media Coverage, Third Party Advisory
• disclosure@vulncheck.com — Patch
• disclosure@vulncheck.com — Issue Tracking, Patch
• disclosure@vulncheck.com — Release Notes
• disclosure@vulncheck.com — Patch, Third Party Advisory