RCE in Nltk
CVE-2026-62388
NLTK versions before 3.10.0 default to ENFORCE=False in pathsec.py, causing all security validation functions to emit warnings instead of raising exceptions. Attackers can bypass path traversal and pickle deserialization protections by exploiting the disabled security controls that are only active when manually enabled.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (41.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 (Exploit, vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/nltk-before-insecure-default-configuration-pathsec (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-62388?
- CVE-2026-62388 is a high-severity vulnerability in Nltk, classified under Initialization of a Resource with an Insecure Default. CVSS score: 7.5/10. Published 2026-08-22.
- How severe is CVE-2026-62388?
- High severity. CVSS v3 base score is 7.5 out of 10.