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CVE-2025-71408GHSA-848C-C2CX-J7QXPYSEC-2026-3657

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

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 3.9.3
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: total

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: total

  3. Record last updated

Affected versions

  • ntlk ntlk

    fixed in 3.9.3

  • nltkPyPI

    fixed in 3.9.3

References 5

aydinnyunus.github.io

GitHub · nltk/nltk

vulncheck.com