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.
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References
History
Fri, 24 Jul 2026 21:45:00 +0000
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| 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. | |
| Title | NLTK < 3.9.2 Eval Injection via collocations.py Command-Line Arguments | |
| Weaknesses | CWE-95 | |
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cvssV3_1
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MITRE
Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-07-24T21:18:01.049Z
Reserved: 2026-07-24T20:57:08.784Z
Link: CVE-2025-71408
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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