Three critical Fortinet sandbox bugs splattered by unknown attackers

Three critical flaws in Fortinet’s sandbox that allow remote attackers to bypass authentication, escalate privileges, and execute malicious code are under active exploitation, according to threat intelligence firm Defused. Fortinet patched two of the three flaws, CVE-2026-39813 and CVE-2026-39808, in April and the third, CVE-2026-25089 last week. All three bugs received 9.1 CVSS ratings, and, at the time, the vendor said that there were no reports of active exploitation.