CVE-2026-54353
@budibase/backend-core has potential SSRF DNS rebinding bypass in outbound fetch validation
Impact
Budibase is an open-source low-code platform. Prior to 3.39.9, authenticated users with automation permissions can bypass Budibase's SSRF blacklist through DNS rebinding. The outbound fetch flow validates a hostname against the blacklist before the request is sent, but the actual socket connection later performs a separate DNS lookup through node-fetch. Since the validated IPs are never pinned to the connection, an attacker-controlled hostname can return a public IP during validation and a private/internal IP during the real connection. This results in a non-blind SSRF primitive against internal services reachable from the Budibase host, including loopback, RFC1918 ranges, and cloud metadata endpoints. This vulnerability is fixed in 3.39.9.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @budibase/backend-core | < 3.39.9 | 3.39.9 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Budibase | Budibase | before 3.39.9 |