On May 6, 2026, Palo Alto Networks published a security advisory for CVE-2026-0300, a critical unauthenticated buffer overflow vulnerability affecting PAN-OS PA-Series and VM-Series firewall appliances. Prisma Access, Cloud NGFW, and Panorama appliances are not affected by this vulnerability.
The vulnerability carries a CVSSv4 score of 9.3 and has been confirmed as exploited in the wild by the vendor. CVE-2026-0300 is a buffer overflow (CWE-787) in the User-ID™ Authentication Portal (also known as Captive Portal), a non-default PAN-OS feature used to map IP addresses to usernames. An unauthenticated remote attacker can exploit this vulnerability by sending specially crafted packets to a device with the Authentication Portal enabled, achieving arbitrary code execution with root privileges on the affected firewall. No authentication or user interaction is required.
Read more…
Source: Rapid7
Sign up for the Cyber Security Review Newsletter
The latest cyber security news and insights delivered right to your inbox
Related:
- Fortinet fixes bug letting unauthenticated hackers run code as root
July 20, 2021
Fortinet has released updates for its FortiManager and FortiAnalyzer network management solutions to fix a serious vulnerability that could be exploited to execute arbitrary code with the highest privileges. Both FortiManager and FortiAnalyzer are enterprise-grade network management solutions for environments with up to 100,000 devices. They are available as a physical appliance, as a virtual machine, ...
- iPhones running latest iOS hacked to deploy NSO Group spyware
July 19, 2021
Human rights non-governmental organization Amnesty International and non-profit project Forbidden Stories revealed in a recent report that they found spyware made by Israeli surveillance firm NSO Group deployed on iPhones running Apple’s latest iOS release, hacked using zero-day zero-click iMessage exploits. “Amnesty International has observed evidence of compromise of the iPhone XR of an Indian journalist ...
- iPhone WiFi bug morphs into zero-click hacking, but there’s a fix
July 19, 2021
Security researchers investigating a bug that crashed the Wifi service on iPhones found that it could be exploited for remote code execution without user interaction. When initially disclosed, the bug could disable an iPhone’s WiFi connection after trying to connect to a network with a name (SSID) that included a special character. Read more… Source: Bleeping Computer
- UK and White House blame China for Microsoft Exchange Server hack
July 19, 2021
The UK government has formally laid the blame for the Microsoft Exchange Server cyberattack at the feet of China. On Monday, the government joined others — including the victim company itself, Microsoft — in claiming the cyberattack was the work of Chinese state-sponsored hackers, namely Hafnium, an advanced persistent threat (APT) group. The United States, NATO, and ...
- Microsoft: New Unpatched Bug in Windows Print Spooler
July 16, 2021
Another vulnerability separate from PrintNightmare allows for local elevation of privilege and system takeover. Microsoft has warned of yet another vulnerability that’s been discovered in its Windows Print Spooler that can allow attackers to elevate privilege to gain full user rights to a system. The advisory comes on the heels of patching two other remote code-execution ...
- Bug bounty platform urges need for firms to have vulnerability disclosure policy
July 16, 2021
Organisations should provide a proper channel through which anyone can report vulnerabilities in their systems. This will ensure potential security holes can be identified and plugged before they are exploited. Establishing a vulnerability disclosure policy (VDP) also would provide assurance to anyone, such as security researchers, acting in good faith that they would not face prosecution ...