CVE-2026-126181 is a vulnerability in Fortinet FortiManager versions 7.2 (all versions), 7.4.0 through 7.4.11, 7.6.0 through 7.6.7, and 8.0.0 through 8.0.1. It involves the use of hard-coded credentials that may allow an adjacent-network authenticated attacker with user permission to join the FGFM configuration-sync mesh using the default pre-shared key.