Recently recommended for production use as of February 2026 [34]. Version 7.6.5: Marked the official transition of the 7.6 branch into the
curl -k -X POST https://<fortigate-ip>/api/v2/monitor/system/firmware/upgrade \ -H "Authorization: Bearer <token>" \ -d ""file": "FGT_100F-v7.4.5-build.FORTINET.out""
The most frequent mistake organizations make is assuming they can upgrade from FortiOS 6.4 to 7.4 directly.