PyPI/nltk CVE-2026-12259, CVE-2026-63310: medium 5.3

NLTK: Missing Post-Download Integrity Verification Allows Malicious Package Injection

Action: Upgrade nltk to 3.9.3 or later.

pip install nltk==3.9.3

Affected

Fixed versions

Sources

• osv: GHSA-5wp5-5229-5g6q
• https://github.com/nltk/nltk/security/advisories/GHSA-5wp5-5229-5g6q
• https://nvd.nist.gov/vuln/detail/CVE-2026-12259
• https://github.com/nltk/nltk/pull/3449
• https://github.com/nltk/nltk/commit/0e26734a61094b628d93e26dc18dd7302567ac46
• https://github.com/nltk/nltk
• https://github.com/nltk/nltk/releases/tag/3.9.3
• https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3729.yaml
• https://huntr.com/bounties/659ccf6d-12d4-4d4a-84c0-078633c35a5d
• https://www.vulncheck.com/advisories/nltk-before-missing-post-download-integrity-verification

CVE-2026-12259, CVE-2026-63310 · published 2026-09-08T15:27:55Z · modified 2026-10-16T10:56:05.808390648Z · JSON