CVE catalog
CVE-2026-0300
A buffer overflow vulnerability in the User-ID™…
Palo Alto Networks PAN-OS contains an out-of-bounds write vulnerability in the User-ID Authentication Portal (aka Captive Portal) service that can allow an unauthenticated attacker to execute arbitrary code with root privileges on the PA-Series and VM-Series firewalls by sending specially crafted packets.
- Severity
- Critical · CVSS 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Published
- Source
- [NVD] · [CVE record]
- Exploitation
- CISA Known Exploited Vulnerabilities
- EPSS
- 41.71% · Oct 27, 2026
Reported versions and fixes
Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.
Version impact has not been established. The original provider fields are retained below.
Provider details and historical evidence
Original provider fields
{
"package_releases": [],
"fixed_versions": [],
"distribution_packages": [
{
"name": "pan-os",
"ecosystem": "cpe",
"fixed_version": ""
},
{
"name": "pan-os",
"ranges": [],
"ecosystem": "cpe",
"fixed_version": "",
"provider_record_id": "NVD-CVE-2026-0300"
}
]
}OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.
Observed:
References
- [https://cert-portal.siemens.com/productcert/csaf/ssa-967325.json]
- [https://cert-portal.siemens.com/productcert/html/ssa-967325.html]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-0300]
- [https://security.paloaltonetworks.com/CVE-2026-0300]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1366.json]
- [https://www.cisa.gov/known-exploited-vulnerabilities-catalog]
- [https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-0300]
[CERT-Bund public advisories] · [CISA cybersecurity advisories] · [CISA Known Exploited Vulnerabilities (OSINT)] · [FIRST EPSS] · [National Vulnerability Database (NVD)]