Vulnerability Description
NLTK before 3.10.3 contains a remote code execution vulnerability in AllowlistUnpickler that validates only the pickle module string and not the global name, allowing attackers to resolve dotted names by attribute traversal to callables outside the allowlisted namespace. Attackers can craft untrusted transition-parser models that execute arbitrary commands when TransitionParser.parse loads the model through allowlisted_pickle_load.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/nltk/nltk
- https://github.com/nltk/nltk/blob/v3.10.2/nltk/picklesec.py#L119-L124
- https://github.com/nltk/nltk/commit/c3e37113742a1ebeeb4f2ca58941f320f98805ea
- https://www.vulncheck.com/advisories/nltk-through-remote-code-execution-via-allo
FAQ
What is CVE-2026-71513?
CVE-2026-71513 is a vulnerability with a CVSS score of 8.8 (HIGH). NLTK before 3.10.3 contains a remote code execution vulnerability in AllowlistUnpickler that validates only the pickle module string and not the global name, allowing attackers to resolve dotted names...
How severe is CVE-2026-71513?
CVE-2026-71513 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-71513?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.