# Nltk vulnerabilities

Source: https://junglewise.ai/threats/technologies/nltk-nltk  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Updated: 9 November 2026, 03:07 UTC. Rebuilt every hour.  
Data: https://junglewise.ai/threats/technologies/nltk-nltk.json  
License: CC BY 4.0 with a link back

Junglewise Threat Intelligence has tracked 6 vulnerabilities in Nltk: 0 in the last 7 days and 0 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-12372, was published on 9 August 2026.

## Counts

- Last 7 days: 0
- Last 30 days: 0
- Last 90 days: 0
- All time: 6 (0 critical, 0 exploited in the wild)

## About Nltk

Python library for natural language processing tasks including tokenization, stemming, and parsing.

## Latest Nltk vulnerabilities

- [CVE-2026-12372: NLTK network URL validation permits SSRF to RFC 6598 shared-address-space hosts](https://junglewise.ai/threats/cve-2026-12372-pysec-2026-3955-a-server-side-request-forgery-ssrf-vulnerability) (low, CVSS 3.7, published 9 Aug 2026)
- [CVE-2026-12259: NLTK missing post-download integrity verification](https://junglewise.ai/threats/cve-2026-12259-nltk-missing-post-download-integrity-verification) (medium, CVSS 6.5, published 3 Aug 2026)
- [CVE-2026-12252: NLTK arbitrary code execution in Stanford interface classes](https://junglewise.ai/threats/cve-2026-12252-nltk-arbitrary-code-execution-in-stanford-interface-classes) (high, CVSS 7.8, published 4 Jul 2026)
- [CVE-2026-33236: NLTK path traversal in downloader component](https://junglewise.ai/threats/cve-2026-33236-nltk-path-traversal-in-downloader-component) (high, CVSS 8.1, published 20 Mar 2026)
- [CVE-2026-0846: NLTK arbitrary file read in nltk.util.filestring](https://junglewise.ai/threats/cve-2026-0846-nltk-arbitrary-file-read-in-nltk-util-filestring) (high, CVSS 8.6, published 9 Mar 2026)
- [CVE-2021-3828: PYSEC-2021-356 - nltk is vulnerable to Inefficient Regular Expression Complexity](https://junglewise.ai/threats/cve-2021-3828-nltk-redos-in-comparative-sentence-parsing) (low, CVSS 3.1, published 27 Sep 2021)

## Most severe Nltk vulnerabilities

- [CVE-2026-0846: NLTK arbitrary file read in nltk.util.filestring](https://junglewise.ai/threats/cve-2026-0846-nltk-arbitrary-file-read-in-nltk-util-filestring) (high, CVSS 8.6, published 9 Mar 2026)
- [CVE-2026-33236: NLTK path traversal in downloader component](https://junglewise.ai/threats/cve-2026-33236-nltk-path-traversal-in-downloader-component) (high, CVSS 8.1, published 20 Mar 2026)
- [CVE-2026-12252: NLTK arbitrary code execution in Stanford interface classes](https://junglewise.ai/threats/cve-2026-12252-nltk-arbitrary-code-execution-in-stanford-interface-classes) (high, CVSS 7.8, published 4 Jul 2026)
- [CVE-2026-12259: NLTK missing post-download integrity verification](https://junglewise.ai/threats/cve-2026-12259-nltk-missing-post-download-integrity-verification) (medium, CVSS 6.5, published 3 Aug 2026)
- [CVE-2026-12372: NLTK network URL validation permits SSRF to RFC 6598 shared-address-space hosts](https://junglewise.ai/threats/cve-2026-12372-pysec-2026-3955-a-server-side-request-forgery-ssrf-vulnerability) (low, CVSS 3.7, published 9 Aug 2026)
- [CVE-2021-3828: PYSEC-2021-356 - nltk is vulnerable to Inefficient Regular Expression Complexity](https://junglewise.ai/threats/cve-2021-3828-nltk-redos-in-comparative-sentence-parsing) (low, CVSS 3.1, published 27 Sep 2021)

## Vulnerabilities per week

Nothing was published in the last eight weeks.

| Week of | Vulns | Critical | Exploited |
| --- | --- | --- | --- |
| 17 Aug 2026 | 0 | 0 | 0 |
| 24 Aug 2026 | 0 | 0 | 0 |
| 31 Aug 2026 | 0 | 0 | 0 |
| 7 Sep 2026 | 0 | 0 | 0 |
| 14 Sep 2026 | 0 | 0 | 0 |
| 21 Sep 2026 | 0 | 0 | 0 |
| 28 Sep 2026 | 0 | 0 | 0 |
| 5 Oct 2026 | 0 | 0 | 0 |
| 12 Oct 2026 | 0 | 0 | 0 |
| 19 Oct 2026 | 0 | 0 | 0 |
| 26 Oct 2026 | 0 | 0 | 0 |
| 2 Nov 2026 | 0 | 0 | 0 |
| 9 Nov 2026 | 0 | 0 | 0 |

## Sources

NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "Nltk vulnerabilities", https://junglewise.ai/threats/technologies/nltk-nltk, 9 November 2026.