CRITICAL: Three FortiSandbox Flaws Under Active Exploitation as Defenders Race to Patch
Defused Cyber reported active exploitation of three CVSS 9.1 FortiSandbox vulnerabilities inside a 24-hour window. CVE-2026-39813, CVE-2026-39808, and CVE-2026-25089 allow unauthenticated remote code execution and authentication bypass on the appliance that other Fortinet products trust to verdict malware. Patches are available, but the 4.2 branch requires migration to a supported release.