{"id":"CVE-2026-33236","aliases":["GHSA-469j-vmhf-r6v7","PYSEC-2026-2237"],"url":"https://o3.security/vulnerability/CVE-2026-33236","summary":"NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite","details":"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.","published":"2026-03-20T22:47:10.308Z","modified":"2026-07-23T03:56:27.670211390Z","cvss":{"score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"nltk","fixedVersion":null}],"fix":{"url":"https://github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a","label":"nltk/nltk@89fe2ec"},"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33236.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10184"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:19712"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:37275"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:42644"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-33236"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33236.json"},{"type":"ADVISORY","url":"https://github.com/nltk/nltk/security/advisories/GHSA-469j-vmhf-r6v7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33236"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2449824"},{"type":"FIX","url":"https://github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-23T03:56:27.670211390Z"}}