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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (33.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/nltk/nltk/security/advisories/GHSA-72r2-7mfr-5xr9 (Exploit, vendor-advisory, Vendor Advisory)
- www.vulncheck.com/advisories/nltk-before-arbitrary-file-read-via-filesystempath… (Third Party Advisory, third-party-advisory)
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.