---
cve: "CVE-2026-0300"
severity: "CRITICAL"
cvss: 9.3
epss: "32.1%"
vendor: "Palo Alto Networks"
kev: true
exploited: true
published: "2026-05-06 19:16:35"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-06T22:16:46+02:00"
---

# CVE-2026-0300

> 9.3 CRITICAL · ⚠️ CISA KEV (123 Tage) · 🔓 Exploited

## Beschreibung

A buffer overflow vulnerability in the User-ID™ Authentication Portal (aka Captive Portal) service of Palo Alto Networks PAN-OS software allows an unauthenticated attacker to execute arbitrary code with root privileges on the PA-Series and VM-Series firewalls by sending specially crafted packets. 

The risk of this issue is greatly reduced if you secure access to the User-ID™ Authentication Portal per the  best practice guidelines https://knowledgebase.paloaltonetworks.com/KCSArticleDetail  by restricting access to only trusted internal IP addresses.

Prisma Access, Cloud NGFW and Panorama appliances are not impacted by this vulnerability.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N/E:A/AU:Y/R:U/V:C/RE:M/U:Red
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Referenzen

- <https://security.paloaltonetworks.com/CVE-2026-0300>
- <https://cert-portal.siemens.com/productcert/html/ssa-967325.html>
- <https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-0300>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-0300) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_