Budibase: Unauthenticated user information disclosure via public tenant user lookup endpoint

Exploitation

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

CVSS

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

EPSS

• CVE-2026-73406: 0.51% estimated exploitation activity in the next 30 days; percentile 43.47 (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 Budibase Worker service exposes a public, unauthenticated API endpoint (GET /api/global/users/tenant/:id) that returns sensitive user information including tenantId, userId, email, and ssoId. The endpoint is registered in the PUBLICENDPOINTS list with a TODO comment acknowledging it "should be an internal API." Any unauthenticated party can enumerate user emails or IDs to extract sensitive tenant and user metadata, enabling targeted attacks against multi-tenant deployments. Details Public endpoint registration at packages/worker/src/api/index.ts lines 56-59: This endpoint is listed in PUBLICENDPOINTS, which is passed to auth.buildAuthMiddleware(PUBLICENDPOINTS) at line 154. When a request matches a public endpoint pattern, the authentication middleware sets ctx.publicEndpoint = true and calls next() without performing any authentication (verified at packages/backend-core/src/middleware/authenticated.ts lines 124-126, 249-251). All subsequent middleware also skips for…

Published by the source

24 Jul 2026, 21:25 UTC

Last modified by the source

12 Aug 2026, 19:26 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hr66-5mqr-8mpx

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hr66-5mqr-8mpx

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# Patch Next advisory brief: CVE-2026-73406

Advisory: Budibase: Unauthenticated user information disclosure via public tenant user lookup endpoint
IDs: CVE-2026-73406, GHSA-hr66-5mqr-8mpx
Record: https://patchnext.com/advisories/cve-2026-73406 (revision 2, source checked 26 Oct 2026, 13:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @budibase/server: affected <= 3.38.1

## 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
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## 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-hr66-5mqr-8mpx (OSV record GHSA-hr66-5mqr-8mpx lists affected ranges: npm @budibase/server >=0 <=3.38.1)
- Verified: https://github.com/advisories/GHSA-hr66-5mqr-8mpx (GitHub-reviewed advisory GHSA-hr66-5mqr-8mpx lists affected ranges: npm @budibase/server >=0 <=3.38.1)

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