{"cvss":9.3,"datePublished":"2026-05-05T00:00:00Z","dateUpdated":"2026-05-05T00:00:00Z","description":"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.","dueDate":"2026-05-09T00:00:00Z","id":"CVE-2026-0300","kev_catalogs":["vulncheck"],"knownRansomwareCampaignUse":"Known","product":"PAN-OS","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.","severity":"CRITICAL","source":"vulncheck_kev","title":"Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability","vendor":"Palo Alto Networks"}