PyPI/nltk CVE-2026-78683: critical, EPSS 0.51%

NLTK: Unsafe Pickle Deserialization in TransitionParser Allows Remote Code Execution

Action: Upgrade nltk to 3.10.0 or later.

pip install nltk==3.10.0

Affected

Fixed versions

Sources

• osv: GHSA-rhp5-r9x4-f5g2
• https://github.com/nltk/nltk/security/advisories/GHSA-rhp5-r9x4-f5g2
• https://nvd.nist.gov/vuln/detail/CVE-2026-78683
• https://github.com/nltk/nltk/pull/3631
• https://github.com/nltk/nltk/commit/f26b3753038d937b68145daf15e9636f8451053c
• https://github.com/nltk/nltk
• https://github.com/nltk/nltk/releases/tag/v3.10.0
• https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3734.yaml
• https://www.vulncheck.com/advisories/nltk-before-remote-code-execution-via-unsafe-pickle-deserialization

CVE-2026-78683 · published 2026-09-08T16:41:11Z · modified 2026-09-08T16:45:04.193165862Z · JSON