Fortinet patched two critical RCE flaws Tuesday. CVE-2026-44277 in FortiAuthenticator (Fortinet's IAM/MFA platform) lets unauthenticated attackers execute code via crafted requests. CVE-2026-26083 (CVSS 9.1) in FortiSandbox's web UI lets unauthenticated attackers run code via HTTP requests. Neither is confirmed exploited yet, but Fortinet products have a long exploitation history - CISA flagged FortiClient EMS as actively exploited in April. FortiSandbox is the threat-detection backbone for many Fortinet-centric SOCs; FortiAuthenticator gates MFA and SSO.
Day-after recovery: a PoC exploit for a critical vulnerability in Fortinet's FortiSandbox product has been publicly available since April 17. CVE-2026-39808 allows an unauthenticated attacker to execute arbitrary code on affected appliances via the web management interface. FortiSandbox is Fortinet's network-based malware analysis product used to inspect suspicious files before they reach endpoints. Because it sits in the malware analysis path, a compromised FortiSandbox gives attackers visibility into every suspicious file your environment has flagged, including real phishing attempts and incident samples. The PoC release doesn't indicate confirmed in-the-wild exploitation yet, but based on recent patterns the window between public PoC and mass scanning is typically measured in hours. CISA has not yet added this to KEV.
If you patched FortiClient EMS for CVE-2026-21643 two weeks ago by upgrading to 7.4.5, you're now vulnerable to a new zero-day. CVE-2026-35616 is a CVSS 9.1 pre-authentication API access bypass affecting versions 7.4.5 and 7.4.6 - the exact versions customers upgraded to. Defused Cyber spotted exploitation in the wild starting March 31. Fortinet released an emergency weekend hotfix on Saturday, with watchTowr noting attackers deliberately timed this for the Easter holiday when security teams are at half strength.
A CVSS 9.1 SQL injection flaw in Fortinet's FortiClient Endpoint Management Server is now being exploited in the wild - four days before anyone flagged it publicly. An attacker only needs one crafted HTTP request with a malicious Site header to execute arbitrary SQL against the backing PostgreSQL database, no credentials required. Roughly 1,000 to 2,400 FortiClient EMS instances are exposed to the internet, mostly in the US and Europe.
TrustStrike Labs