Path Traversal in Nltk
CVE-2026-62383
nltk versions before 3.10.2 contain a symlink-based arbitrary file read vulnerability in IPIPANCorpusReader methods that bypass nltk.pathsec validation entirely. Attackers can place a symlink in the corpus root directory and read arbitrary files accessible to the process by calling channels(), domains(), categories(), or fileids() methods with the symlink filename.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (7.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000
Affected products
Weakness classification (CWE)
References
- github.com/nltk/nltk/security/advisories/GHSA-3hhw-38pf-pxj6 (Exploit, vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/nltk-ipipancorpusreader-symlink-arbitrary-file-read (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-62383?
- CVE-2026-62383 is a medium-severity vulnerability in Nltk, classified under Path Traversal. CVSS score: 5.5/10. Published 2026-08-22.
- How severe is CVE-2026-62383?
- Medium severity. CVSS v3 base score is 5.5 out of 10.