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.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-95"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71408.json"
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "3.9.3"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "66f14096d952ec8f04934f515e027534bd4eb0ac"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "3.9.3",
"range": [
{
"fixed": "4154eb85e832f266660a09286c7e37e308292284"
}
],
"source": "REFERENCES_TAG"
}
]
}