IA Squad
SearchPT
js · @budibase/serverCritical

@budibase/server OAuth2 SSRF via unblacklisted fetchToken URL

The OAuth2 SDK's fetchToken function POSTs to a builder-supplied URL without blacklist checking.

23 Jun 2026Read 1 minSeverity: act now

What changed

The OAuth2 SDK's fetchToken function POSTs to a builder-supplied URL without blacklist checking. The Joi schema for the OAuth2 URL lacks scheme or host restrictions.

Who it affects

All Budibase deployments (Cloud and self-hosted) using OAuth2 validation. Any builder account can exploit this.

What to do today

Apply the recommended fix: call blacklist.isBlacklisted before the fetch and set redirect: 'manual' on fetchConfig, or replace the fetch call with fetchWithBlacklist.

The trail
Collected Audited Written Published