CVE-2026-79657
Published:August 25, 2026
Updated:September 24, 2026
NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and numpy.f2py.crackfortran.myeval through pickle REDUCE to execute arbitrary commands during model or tokenizer artifact loading.
Affected Packages
nltk (CONDA):
Affected version(s) >=2.0.3 <3.10.3Fix Suggestion:
Update to version 3.10.3nltk (CONDA):
Affected version(s) >=2.0.3 <3.10.3Fix Suggestion:
Update to version 3.10.3nltk (PYTHON):
Affected version(s) >=2.0b4 <3.10.3Fix Suggestion:
Update to version 3.10.3nltk (PYTHON):
Affected version(s) >=0.8 <3.10.3Fix Suggestion:
Update to version 3.10.3Related Resources (8)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
EPSS
Base Score:
1.21