Budibase: Server-Side Request Forgery via REST Connector with Empty Default Blacklist

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.6 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

EPSS

• CVE-2026-31818: 0.38% estimated exploitation activity in the next 30 days; percentile 32.44 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

1. Summary | Field | Value | |-------|-------| | Title | SSRF via REST Connector with Empty Default Blacklist Leading to Full Internal Data Exfiltration | | Product | Budibase | | Version | 3.30.6 (latest stable as of 2026-02-25) | | Component | REST Datasource Integration + Backend-Core Blacklist Module | | Severity | Critical | | Attack Vector | Network | | Privileges Required | Low (Builder role, or QUERY WRITE for execution of pre-existing queries) | | User Interaction | None | | Affected Deployments | All self-hosted instances without explicit BLACKLISTIPS configuration (believed to be the vast majority) | --- 2. Description A critical Server-Side Request Forgery (SSRF) vulnerability exists in Budibase's REST datasource connector. The platform's SSRF protection mechanism (IP blacklist) is rendered completely ineffective because the BLACKLISTIPS environment variable is not set by default in any of the official deployment configurations. When this variable is empty, the blacklist…

Published by the source

3 Apr 2026, 21:34 UTC

Last modified by the source

3 Apr 2026, 21:56 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-7r9j-r86q-7g45

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-7r9j-r86q-7g45

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-7r9j-r86q-7g45

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# Patch Next advisory brief: CVE-2026-31818

Advisory: Budibase: Server-Side Request Forgery via REST Connector with Empty Default Blacklist
IDs: CVE-2026-31818, GHSA-7r9j-r86q-7g45
Record: https://patchnext.com/advisories/cve-2026-31818 (revision 3, source checked 26 Oct 2026, 12:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @budibase/backend-core 3.33.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @budibase/backend-core: affected < 3.33.4; fixed in 3.33.4

## Suggested inspection (read-only)
- `npm ls @budibase/backend-core --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @budibase/backend-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7r9j-r86q-7g45 (GitHub-reviewed advisory GHSA-7r9j-r86q-7g45 lists affected ranges: npm @budibase/backend-core >=0 <3.33.4)
- Verified: https://osv.dev/vulnerability/GHSA-7r9j-r86q-7g45 (OSV record GHSA-7r9j-r86q-7g45 lists affected ranges: npm @budibase/backend-core >=0 <3.33.4 (fixed))

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