critical9.8
CVE-2026-79657
NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific…
Impact
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
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | nltk | <= 3.10.2 | 3.10.3 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Nltk | Nltk | before 3.10.3 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-x99w-6fgc-pmfw
- https://github.com/nltk/nltk/security/advisories/GHSA-x99w-6fgc-pmfw
- https://nvd.nist.gov/vuln/detail/CVE-2026-79657
- https://github.com/nltk/nltk/commit/c3e37113742a1ebeeb4f2ca58941f320f98805ea
- https://github.com/nltk/nltk/releases/tag/v3.10.3
- https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3735.yaml
- https://www.vulncheck.com/advisories/nltk-before-3.10.3-remote-code-execution-via-unsafe-pickle-deserialization