Post-exploit actions for FortiGate compromises

Beyond RC4 for Windows authentication
Microsoft outlined its transition plan to move away from RC4 for authentication and published guidance and tools to facilitate this change.
https://www.microsoft.com/en-us/windows-server/blog/2025/12/03/beyond-rc4-for-windows-authentication
FortiCloud SSO Login Vuln Exploited
Arctic Wolf observed exploit attempts against vulnerable FortiGate appliances.
https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/
FrePBX Vulnerability
Horizon3.ai identified three distinct vulnerabilities in FreePBX. In particular, the authentication by-pass issue should be of concern, but default FreePBX installs do not use the vulnerable web authentication feature.
https://horizon3.ai/attack-research/the-freepbx-rabbit-hole-cve-2025-66039-and-others/