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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
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References
- https://aydinnyunus.github.io/2026/06/07/command-injection-nltk-collocations-eval/
- https://github.com/nltk/nltk/commit/66f14096d952ec8f04934f515e027534bd4eb0ac
- https://github.com/nltk/nltk/pull/3465
- https://github.com/nltk/nltk/releases/tag/3.9.3
- https://www.vulncheck.com/advisories/nltk-eval-injection-via-collocations-py-command-line-arguments
CWEs
CWE-95
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.