CVE-2026-82241: Budibase backend-core SSRF via incomplete default blacklist

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-28 · updated 2026-10-08
Weakness: CWE-918

Description

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 (DEFAULT_BLACKLIST) used by REST datasource query previews. When the default blacklist is active (i.e., a self-hosted deployment has not defined BLACKLIST_IPS), 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 DEFAULT_BLACKLIST.

Affected products

budibase server: before 3.41.3 — fixed in 3.41.3

How to fix

Upgrade to a fixed version: budibase server 3.41.3. Check the vendor advisory for mitigations.

References

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