Called exploited 1 days before disclosure.
Measured from the CVE publication date to the earliest of 3 KEV catalogues that list it.
The life of this vulnerability
- CVE published
- First KEV listing1d
- Last KEV listing1d
- Last sighting3mo
Gaps are compressed to equal steps. The elapsed time is printed under each.
Which catalogues call it exploited
- CISA KEVUS federallisted May 6, 2026
- EUVDENISA, European Unionlisted May 6, 2026
- VulnCheck KEVcommercial researchlisted May 5, 2026
- CIRCLaggregator, mirrors the abovelisted May 6, 2026, not counted
3 catalogues list it. CIRCL aggregates the others and is shown but not counted.
Public exploitation evidence
- reported exploitationwww.tenable.com/blog/the-agentic-ai-threat-cluster-seven-inc
- reported exploitationcyble.com/reports/H1-2026-Global-Threat-Landscape-Report.pdf
- reported exploitationwww.cyfirma.com/research/tracking-ransomware-may-2026/
- reported exploitationwww.proofpoint.com/us/blog/threat-insight/more-cves-same-pla
- reported exploitationransom-isac.org/blog/critical-pan-os-vulnerability/
- reported exploitationunit42.paloaltonetworks.com/captive-portal-zero-day/
8 public reports collected from VulnCheck and CIRCL, first on May 5, 2026. Each links to its original source. We have not verified them.
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.
Required action (CISA)
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.
