WordPress version <4.9 contains a CWE-20 Input Validation vulnerability in thumbnail processing that can result in remote code execution. This attack appears to be exploitable via thumbnail upload by an authenticated user and may require additional plugins in order to be exploited however this has not been confirmed at this time. This issue appears to have been partially, but not completely fixed in WordPress 4.9
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H8.8/CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H