Budibase backend-core (@budibase/backend-core, as used by @budibase/server) omits the shared address space range 100.64.0.0/10 from its default SSRF blacklist (DEFAULTBLACKLIST) used by REST datasource query previews. When the default blacklist is active (i.e., a self-hosted deployment has not defined BLACKLISTIPS), an authenticated user with the Builder permission can submit a REST datasource query preview request to POST /api/queries/preview targeting a reachable HTTP(S) service in the 100.64.0.0/10 range, causing the server to send a request to that target and return its response through the preview flow. Per the advisory, no released fix was identified at the time of publication; remediation is to add 100.64.0.0/10 to DEFAULTBLACKLIST.