---
cve: "CVE-2026-54293"
severity: "HIGH"
cvss: 7.5
epss: "60%"
vendor: "nltk"
kev: false
exploited: false
published: "2026-06-22 19:17:20"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-04T16:19:35+02:00"
---

# CVE-2026-54293

> 7.5 HIGH · 🧪 PoC

## Beschreibung

NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Prior to 3.10.0-rc1, nltk.data.load() in NLTK is vulnerable to path traversal via URL-encoded path separators and traversal segments when using the nltk: URL scheme. The unsafe-path regex check is performed before url2pathname() decodes the %xx sequences (a classic decode-after-check / TOCTOU-style flaw), allowing an attacker to bypass the protection documented in NLTK's SECURITY.md and read arbitrary files from the filesystem. While literal traversal strings such as ../../../etc/passwd are correctly blocked, encoded variants such as %2fetc%2fpasswd, %2e%2e%2f..., and ..%2f..%2f slip past the regex and are subsequently decoded into a real filesystem path. This vulnerability is fixed in 3.10.0-rc1.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Keine | good |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 16a32d680d070254d5744e33fa83f9c0056d5a1f (Commit)

## Referenzen

- <https://github.com/nltk/nltk/security/advisories/GHSA-p4gq-832x-fm9v>
- <https://github.com/nltk/nltk/pull/3575>
- <https://access.redhat.com/errata/RHSA-2026:42644>
- <https://access.redhat.com/errata/RHSA-2026:60520>
- <https://access.redhat.com/security/cve/CVE-2026-54293>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2491486>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54293.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-54293) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_