Budibase: Mass Assignment in Webhook Trigger Allows Cross-Workspace Automation Execution via appId Override

Exploitation

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

CVSS

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

EPSS

• CVE-2026-54351: 0.46% estimated exploitation activity in the next 30 days; percentile 40.02 (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.

Summary The webhook trigger endpoint in Budibase is publicly accessible and passes the full HTTP request body into automation execution parameters. A mass assignment vulnerability in externalTrigger() allows an attacker to overwrite the internal appId property by including it in the webhook POST body. When the automation is processed asynchronously (the default path for webhooks without a collect step), the worker executes the attacker-defined automation in the context of the victim's workspace, granting full read/write access to the victim's database. Details The webhook trigger route is registered as a public endpoint with no authentication: The controller passes the raw request body as fields alongside the server-derived appId: In externalTrigger(), for webhook-triggered automations, params.fields is spread back into params: Because params.fields is spread after params, any key in the attacker's body overwrites the corresponding property in params. An attacker including "appId":…

Published by the source

22 Jun 2026, 23:20 UTC

Last modified by the source

21 Jul 2026, 15:15 UTC

Source last checked

26 Oct 2026, 12:57 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-rgvg-3wpc-h44p

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-rgvg-3wpc-h44p

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# Patch Next advisory brief: CVE-2026-54351

Advisory: Budibase: Mass Assignment in Webhook Trigger Allows Cross-Workspace Automation Execution via appId Override
IDs: CVE-2026-54351, GHSA-rgvg-3wpc-h44p
Record: https://patchnext.com/advisories/cve-2026-54351 (revision 2, source checked 26 Oct 2026, 12:57 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @budibase/server 3.39.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @budibase/server: affected < 3.39.9; fixed in 3.39.9

## Suggested inspection (read-only)
- `npm ls @budibase/server --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/server.
- 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://osv.dev/vulnerability/GHSA-rgvg-3wpc-h44p (OSV record GHSA-rgvg-3wpc-h44p lists affected ranges: npm @budibase/server >=0 <3.39.9 (fixed))
- Verified: https://github.com/advisories/GHSA-rgvg-3wpc-h44p (GitHub-reviewed advisory GHSA-rgvg-3wpc-h44p lists affected ranges: npm @budibase/server >=0 <3.39.9)

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