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.
Affected products
nltk: nltk
References9
- github.com/nltk/nltk/security/advisories/GHSA-469j-vmhf-r6v7 ExploitVendor Advisory
- github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc3423197… Patch
- access.redhat.com/errata/RHSA-2026:10184
- access.redhat.com/errata/RHSA-2026:19712
- access.redhat.com/errata/RHSA-2026:37275
- access.redhat.com/errata/RHSA-2026:42644
- access.redhat.com/security/cve/CVE-2026-33236
- bugzilla.redhat.com/show_bug.cgi?id=2449824
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33236…
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H - EPSS — exploit probability
- 1% percentile: 50 · as of 12 November 2026
- CWE
- CWE-22
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