CVE-2026-63310

EUVD-2026-64335
NLTK before 3.9.3 fails to verify file integrity after downloading packages and before extraction in the downloader module. Attackers can perform man-in-the-middle attacks or DNS poisoning to inject malicious package contents that are extracted without validation.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
7.1 HIGH
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/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
< 3.9.3
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
no-dsa
Common Weakness Enumeration
References
https://github.com/nltk/nltk/security/advisories/GHSA-5wp5-5229-5g6q
https://www.vulncheck.com/advisories/nltk-before-missing-post-download-integrity-verification