{"cve":"CVE-2026-33236","nvd":{"published":"2026-03-20T23:16:47.007","modified":"2026-07-21T12:18:07.627","status":"Modified","description":"NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, the NLTK downloader does not validate the `subdir` and `id` attributes when processing remote XML index files. Attackers can control a remote XML index server to provide malicious values containing path traversal sequences (such as `../`), which can lead to arbitrary directory creation, arbitrary file creation, and arbitrary file overwrite. Commit 89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a patches the issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","score":8.1},"cwes":["CWE-22"],"references":["https://github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a","https://github.com/nltk/nltk/security/advisories/GHSA-469j-vmhf-r6v7","https://access.redhat.com/errata/RHSA-2026:10184","https://access.redhat.com/errata/RHSA-2026:19712","https://access.redhat.com/errata/RHSA-2026:37275"],"products":["nltk:nltk"],"source":"nvd","synced_at":"2026-10-19T22:26:19.218427112+00:00"},"epss":{"cve":"CVE-2026-33236","score":0.006,"percentile":0.48715,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-469j-vmhf-r6v7","url":"https://osv.dev/vulnerability/GHSA-469j-vmhf-r6v7","summary":"NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite","modified":"2026-09-10T03:50:36.939520178Z","packages":[{"ecosystem":"PyPI","name":"nltk","purl":"pkg:pypi/nltk","ranges":["<=3.9.2"],"fixed":[]}]},{"id":"PYSEC-2026-2237","url":"https://osv.dev/vulnerability/PYSEC-2026-2237","summary":"","modified":"2026-07-13T07:15:50.554526751Z","packages":[{"ecosystem":"PyPI","name":"nltk","purl":"pkg:pypi/nltk","ranges":["<3.9.4"],"fixed":["3.9.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}