PAN-OS User-ID Portal Flaw Under Attack
A buffer overflow vulnerability in Palo Alto Networks PAN-OS User-ID Authentication Portal is being actively exploited to achieve remote code execution.
Sourceipa.go.jp — open the original
What to check
- Applies to
- The 1 CVE named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation
- CISA lists CVE-2026-0300 as exploited in the wild.
IPA has issued an alert regarding CVE-2026-0300, a buffer overflow vulnerability affecting the User-ID Authentication Portal component of Palo Alto Networks' PAN-OS. The vendor has confirmed that the vulnerability is already being exploited in the wild by remote attackers, who could leverage it to execute arbitrary code on affected devices. Prisma Access, Cloud NGFW, and Panorama appliances are reportedly not affected by this issue.
Organizations using PAN-OS are urged to check whether the User-ID Authentication Portal feature is enabled and review access restrictions, applying vendor-recommended mitigations if they are exposed. IPA also recommends closely monitoring for vendor patches and applying updates promptly once available, given the active exploitation and potential for expanding attacks.
Mentioned in this report
Source reporting: https://www.ipa.go.jp/security/security-alert/2026/alert20260508.html
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