Vulnerability in Nltk

CVE-2026-65915

NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load() to read arbitrary files accessible to the process user, including credentials and configuration files.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-65915?
CVE-2026-65915 is a medium-severity vulnerability in Nltk, classified under Improper Access Control. CVSS score: 6.5/10. Published 2026-08-22.
How severe is CVE-2026-65915?
Medium severity. CVSS v3 base score is 6.5 out of 10.