If errors returned from MarshalJSON methods contain user controlled data, they may be used to break the contextual auto-escaping behavior of the html/template package, allowing for subsequent actions to inject unexpected content into templates.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:LI:LA:N5.4/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N