CVE-2026-82241 affects Budibase's backend-core package (@budibase/backend-core), which omits the shared address space range 100.64.0.0/10 from its default SSRF blacklist (DEFAULT_BLACKLIST). This omission allows authenticated users with Builder permissions to send crafted REST datasource query preview requests via POST /api/queries/preview to services within the 100.64.0.0/10 range. The server processes these requests and returns the responses, effectively enabling Server-Side Request Forgery (SSRF). The vulnerability only impacts self-hosted deployments that have not overridden the default blacklist via the BLACKLIST_IPS environment variable. No official patch had been released at the time of publication. The recommended remediation is to manually add 100.64.0.0/10 to the DEFAULT_BLACKLIST configuration.