CVE-2026-0300
Act now ● On CISA KEV — actively exploited
Actively exploited — on the CISA KEV list.
CVSS base
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EPSS — probability of exploitation (30 days)
31.7%
98.2th percentile
CISA KEV
Listed
Added 2026-05-06 · patch by 2026-05-09
Weakness / dates
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Published — · modified —
Timeline
- 2026-05-06 — Added to CISA KEV (actively exploited)
- 2026-05-09 — CISA patch-by deadline
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.