🛡️ CVE-2025-71408 on Ubuntu — nltk
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.
Distribution advisory
This page covers CVE-2025-71408 as tracked by Ubuntu, for the package nltk. No fixed version has been recorded for this distribution yet.
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. Rated impact: confidentiality high, integrity high, availability high.
Affected software and timeline
Affected software: nltk. Published on 24 July 2026 and last revised on 29 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
aydinnyunus.github.io (Report)
github.com (Report)
github.com (Report)
github.com (Report)
www.vulncheck.com (Report)
Details
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| nltk | — | — |
References
Similar Threats
- High CVE-2026-12061
- High CVE-2026-12072
- High CVE-2026-12074
- High CVE-2026-12075
- High CVE-2025-71408
Site Security Check
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