---
cve: "CVE-2026-54338"
severity: "MEDIUM"
cvss: 5.3
epss: "28%"
vendor: "jupyterhub"
kev: false
exploited: false
published: "2026-08-07 21:17:29"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-12T22:41:28+02:00"
---

# CVE-2026-54338

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. Prior to 5.5.0, invalid input to form-based login authenticators can place an unbounded attacker-controlled username in failed-login logs, allowing an unauthenticated attacker to consume logging and storage resources. This issue is fixed in version 5.5.0.

## CVSS-Vektor

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

| 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 | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Gering | warn |

## Patch verfügbar (OSV)

- d6dc595f84b7509969686da31d87d6d69e7fce0a (Commit)

## Referenzen

- <https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-p43p-whwx-q52h>
- <https://github.com/jupyterhub/jupyterhub/commit/d6dc595f84b7509969686da31d87d6d69e7fce0a>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-54338) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_