NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization
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.
CVE-2026-79657
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-79657
nltk
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "nltk",
"product": "nltk",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "3.10.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "3.10.3",
"versionType": "semver"
}
],
"packageURL": "pkg:pypi/nltk",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-79657
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #12892 · Revision 1
- Added to Heist Feed
- Publisher date