CVE-2026-33236NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite
- 8.1HighCVSS base score
- 0.61%Exploitation in 30 daysEPSS · top 50% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
Timeline
ID reserved
By GitHub_M
- 2 days later
· 2 days later
Published
- 4 months later
· 4 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H |
| redhat-SADPADP (enrichment) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H |
| NVDNVD · Modified | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.61% · top 50% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
References
References9
- https://github.com/nltk/nltk/security/advisories/GHSA-469j-vmhf-r6v7 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a (opens in a new tab)x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-33236 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2449824 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33236.json (opens in a new tab)x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:10184 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:42644 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:19712 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:37275 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-13887 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-469j-vmhf-r6v7 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-33236)Record last updated .