{
  "id": "cve-2026-0300",
  "cveID": "CVE-2026-0300",
  "vendor": "Palo Alto Networks",
  "product": "PAN-OS",
  "vulnerabilityName": "Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability",
  "shortDescription": "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.",
  "requiredAction": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Until the vendor releases an official fix, the following workaround should be implemented:  - Restrict User-ID Authentication Portal access to only trusted zones.  - Disable User-ID Authentication Portal if not required. 5/13/2026: Palo Alto has released a variety of patches. If these are relevant to your environment, please apply the designated patch.",
  "dateAdded": "2026-05-06",
  "dueDate": "2026-05-09",
  "knownRansomware": false,
  "cwes": [
    "CWE-787"
  ],
  "notes": "https://security.paloaltonetworks.com/CVE-2026-0300 ; https://nvd.nist.gov/vuln/detail/CVE-2026-0300",
  "sources": [
    {
      "label": "NVD",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-0300"
    },
    {
      "label": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog"
    },
    {
      "label": "security.paloaltonetworks.com",
      "url": "https://security.paloaltonetworks.com/CVE-2026-0300"
    },
    {
      "label": "nvd.nist.gov",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-0300"
    }
  ],
  "cvss": {
    "score": 9.3,
    "severity": "CRITICAL",
    "version": "4.0",
    "vector": "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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:C/RE:M/U:Red"
  },
  "epss": {
    "score": 0.31725,
    "percentile": 0.98186
  },
  "timeline": [
    {
      "date": "2026-05-06",
      "event": "Added to the CISA KEV catalog"
    },
    {
      "date": "2026-05-09",
      "event": "CISA remediation due date (BOD 22-01)"
    }
  ],
  "status": "past due"
}