Budibase: Account Enumeration via Login Lockout Response Differential

Exploitation

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

CVSS

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

EPSS

• CVE-2026-73306: 0.44% estimated exploitation activity in the next 30 days; percentile 38.12 (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 login lockout mechanism in Budibase creates an observable response discrepancy that allows unauthenticated attackers to enumerate valid email addresses. When an existing user's account is locked after 5 failed login attempts, the server returns a distinct 403 response with X-Account-Locked: 1 and Retry-After: 900 headers plus the message "Account temporarily locked." For non-existing users, the response is always a generic 403 "Unauthorized" regardless of attempt count, because the lockout counter is never incremented. Details The vulnerability exists in two files that implement the login lockout feature: packages/worker/src/middleware/lockout.ts:18-36 — The lockout middleware only blocks requests for users that exist in the database AND are locked: packages/worker/src/api/controllers/global/auth.ts:127-141 — The login handler only increments the failure counter for existing users: Execution flow for existing users (after 5 failed attempts): 1. lockout middleware →…

Published by the source

24 Jul 2026, 21:43 UTC

Last modified by the source

12 Aug 2026, 19:11 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-cr7p-cr3q-h5cm

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-cr7p-cr3q-h5cm

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# Patch Next advisory brief: CVE-2026-73306

Advisory: Budibase: Account Enumeration via Login Lockout Response Differential
IDs: CVE-2026-73306, GHSA-cr7p-cr3q-h5cm
Record: https://patchnext.com/advisories/cve-2026-73306 (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: Medium (CVSS 5.3)
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-cr7p-cr3q-h5cm (OSV record GHSA-cr7p-cr3q-h5cm lists affected ranges: npm @budibase/server >=0 <=3.38.1)
- Verified: https://github.com/advisories/GHSA-cr7p-cr3q-h5cm (GitHub-reviewed advisory GHSA-cr7p-cr3q-h5cm lists affected ranges: npm @budibase/server >=0 <=3.38.1)

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