CVE-2026-54356 Budibase authenticated arbitrary S3 signed upload URL issuance via `/api/attachments/:datasourceId/url`
Authenticated users can generate signed S3 URLs for arbitrary buckets, potentially exposing or modifying data in cloud storage.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-54356?
CVE-2026-54356 is a high-severity missing authorization vulnerability in budibase, published on 17 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Budibase is an open-source low-code platform. Prior to 3.41.3, POST /api/attachments/:datasourceId/url in packages/server/src/api/routes/static.ts and packages/server/src/api/controllers/static/index.ts allows an authenticated published-app user with the BASIC role to supply attacker-controlled bucket and key values and obtain signedUrl and publicUrl values backed by stored S3 datasource credentials. This issue is fixed in version 3.41.3.
Weakness: CWE-862
Which versions are affected by CVE-2026-54356?
2 open source packages ship an affected version, including @budibase/server.
| Package | Affected | Fixed in |
|---|---|---|
@budibase/server npm | All versions to 3.38.1 | None |
@budibase/server npm | All versions to 3.38.1 | None |
How do I fix CVE-2026-54356?
No fix has been published for CVE-2026-54356 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-54356 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54356 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-6x9p-4r67-5gjx.