View CSAF Summary A buffer overflow vulnerability in the User-ID™ Authentication Portal (aka Captive Portal) service of Palo Alto Networks PAN-OS software allows an unauthenticated attacker to execute arbitrary code with root privileges on the PA-Series and VM-Series firewalls by sending specially crafted packets. Siemens is preparing fix versions and recommends countermeasures for products where fixes are not, or not yet available. Customers are advised to consult and implement the workarounds provided in Palo Alto Networks' upstream security notifications. [1] https://security.paloaltonetworks.com/ The following versions of Siemens RUGGEDCOM APE1808 Devices are affected: RUGGEDCOM APE1808 vers:all/* (CVE-2026-0300) CVSS Vendor Equipment Vulnerabilities v3 10 Siemens Siemens RUGGEDCOM APE1808 Devices Out-of-bounds Write Background Critical Infrastructure Sectors: Critical Manufacturing Countries/Areas Deployed: Worldwide Company Headquarters Location: Germany Vulnerabilities Expand All + CVE-2026-0300 A buffer overflow vulnerability in the User-ID™ Authentication Portal (aka Captive Portal) service of Palo Alto Networks PAN-OS software allows an unauthenticated attacker to execute arbitrary code with root privileges on the PA-Series and VM-Series firewalls by sending specially crafted packets. View CVE Details Affected Products Siemens RUGGEDCOM APE1808 Devices Vendor...

Palo Alto says hackers exploited PAN-OS zero-day CVE-2026-0300 for weeks, gaining root access to exposed firewalls and hiding traces. Palo Alto Networks warned that suspected state-sponsored hackers have been exploiting the critical PAN-OS zero-day CVE-2026-0300 for nearly a month. After exploiting the flaw, attackers deployed tunneling tools such as EarthWorm and ReverseSocks5, used stolen credentials […]

Palo Alto Networks has disclosed that threat actors may have attempted to unsuccessfully exploit a recently disclosed critical security flaw as early as April 9, 2026. The vulnerability in question is CVE-2026-0300 (CVSS score: 9.3/8.7), a buffer overflow vulnerability in the User-ID Authentication Portal service of Palo Alto Networks PAN-OS software that could allow an unauthenticated attacker

Palo Alto Networks believes the in-the-wild exploitation of a zero-day vulnerability (CVE-2026-0300) in its firewalls is likely the work of state-sponsored threat actors. A flaw with no patch (yet) CVE-2026-0300 is a buffer overflow vulnerability in the User-ID Authentication Portal service of Palo Alto Networks PAN-OS software, and can be exploited by unauthenticated attackers sending specially crafted packets to internet-facing User-ID Authentication Portals. The flaw affects Palo Alto Networks’ PA-Series and VM-Series firewalls, and the … More → The post State-sponsored hackers likely behind zero-day attacks on Palo Alto firewalls appeared first on Help Net Security .

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds a flaw in Palo Alto Networks PAN-OS to its Known Exploited Vulnerabilities catalog The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added a flaw in the Palo Alto Networks PAN-OS, tracked as CVE-2026-0300 (CVSS score of 9.3), to its Known Exploited Vulnerabilities (KEV) catalog. The flaw is a buffer […]

Unit 42 details CVE-2026-0300, a buffer overflow vulnerability in the PAN-OS User-ID Authentication Portal. Read now for details. The post Threat Brief: Exploitation of PAN-OS Captive Portal Zero-Day for Unauthenticated Remote Code Execution appeared first on Unit 42 .