CVE-2026-79657

EUVD-2026-65440
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
9.8 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
nltknltk
𝑥
< 3.10.3
CNA
Debian logo
Debian Releases
Debian Product
Codename
nltk
bookworm
vulnerable
bullseye
vulnerable
forky
3.10.3-1
fixed
sid
3.10.3-1
fixed
trixie
vulnerable
Common Weakness Enumeration
References
https://github.com/nltk/nltk/security/advisories/GHSA-x99w-6fgc-pmfw
https://www.vulncheck.com/advisories/nltk-before-3.10.3-remote-code-execution-via-unsafe-pickle-deserialization
https://github.com/nltk/nltk/security/advisories/GHSA-x99w-6fgc-pmfw