# CVE-2026-73409: Budibase arbitrary filesystem path read oracle in MongoDB datasource

Source: https://junglewise.ai/threats/cve-2026-73409-budibase-arbitrary-filesystem-path-read-oracle-in-mongodb  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-24. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-73409 · Severity: medium · CVSS 4 · Published 2026-07-24

Budibase is a low-code application platform that allows builders to create datasources by configuring connections to databases. A vulnerability in the MongoDB datasource configuration allows a builder to supply arbitrary file paths, which the server reads when verifying the connection. By observing different error messages, an attacker can determine whether files exist anywhere on the underlying server filesystem and exfiltrate their contents—potentially accessing secrets, configuration files, and other tenants' data on multi-tenant Budibase Cloud instances.

Technologies: [@budibase/server (npm)](https://junglewise.ai/threats/technologies/budibase-server). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-73409 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-73409 being exploited in the wild.

**How severe is CVE-2026-73409?** Medium severity, with a CVSS score of 4, published 24 July 2026.

**Which products and versions are affected?** @budibase/server (npm) SEMVER:introduced=0,last_affected=3.38.1.

**Is there a fix for CVE-2026-73409?** A patch was published on 2026-07-24: Fixed in version 3.40.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-73409 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-73409?** Check whether you run @budibase/server (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an information disclosure (CWE-209) in packages/server/src/integrations/mongodb.ts. The MongoDB integration passes user-controlled tlsCertificateKeyFile and tlsCAFile configuration fields directly to the MongoDB driver as filesystem paths without validation, filtering, or directory confinement. When a datasource is verified via /api/datasources/verify, the MongoDB driver performs a real filesystem read of the attacker-supplied path. Files that exist but are not valid PEM return a "PEM routines" error; non-existent files return "ENOENT" with the path reflected. This creates a filesystem existence/read oracle. The attack requires authentication as a builder (local attack vector with user interaction to create/verify a datasource). Patches are available in version 3.40.0 and later, implementing PEM-from-content and path restrictions.

## Affected products

- Budibase Budibase <3.40.0

## Identifiers

- CVE-2026-73409
- GHSA-ppr4-5f46-j9c6

## Timeline

- 2026-07-24: disclosed
- 2026-07-24: patched: Fixed in version 3.40.0

## References

- [https://github.com/Budibase/budibase/security/advisories/GHSA-ppr4-5f46-j9c6](https://github.com/Budibase/budibase/security/advisories/GHSA-ppr4-5f46-j9c6)
- [https://github.com/Budibase/budibase/pull/19244](https://github.com/Budibase/budibase/pull/19244)

## Related threats

- [Budibase S3 signed upload URL issuance via attachments endpoint](https://junglewise.ai/threats/cve-2026-54356-budibase-s3-signed-upload-url-issuance-via-attachments-endpoint)
- [Budibase automation SSRF in webhook and integration steps](https://junglewise.ai/threats/cve-2026-35219-budibase-automation-ssrf-in-webhook-and-integration-steps)
- [Budibase S3 presigned URL authorization regression](https://junglewise.ai/threats/cve-2026-72859-budibase-s3-presigned-url-authorization-regression)
- [Budibase MySQL DESCRIBE backtick injection via multipleStatements](https://junglewise.ai/threats/cve-2026-73408-budibase-mysql-describe-backtick-injection-via-multiplestatements)
- [Budibase privilege escalation in public role assignment API](https://junglewise.ai/threats/cve-2026-73305-budibase-privilege-escalation-in-public-role-assignment-api)