CISA lists this Palo Alto Networks PAN-OS vulnerability as known exploited. Check the cited references and original publisher guidance for affected products and remediation.
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.
Product
PAN-OS
Added to KEV
6 May 2026
Federal remediation due
9 May 2026
Known ransomware use
Not reported
Page history
Changes are dated when recorded; day views use the last saved version from that UTC day, and citations stay fixed.
CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.
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.
Risk history is separate from CNA/OSV content history. Daily score drift is retained but only an upward crossing of 10% triggers the prediction change event.
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