CVE-2026-63310

Description

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.

CVSS Vector

References

• https://github.com/nltk/nltk/security/advisories/GHSA-5wp5-5229-5g6q
• https://www.vulncheck.com/advisories/nltk-before-missing-post-download-integrity-verification