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CVE-2026-50136 Budibase CVE debrief

CVE-2026-50136 is a HIGH severity vulnerability in Budibase, an open-source low-code platform. Prior to version 3.39.3, Budibase exposes an unauthenticated endpoint that generates S3 PutObject presigned URLs using credentials stored in a workspace datasource. This endpoint is only protected 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 allows for potential data breaches and unauthorized access. Budibase has fixed this vulnerability in version 3.39.3.

Vendor
Budibase
Product
Unknown
CVSS
HIGH 7.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-26
Original CVE updated
2026-06-30
Advisory published
2026-06-26
Advisory updated
2026-06-30

Who should care

Budibase users and administrators should be aware of this vulnerability and take immediate action to update to version 3.39.3 or later. Additionally, users should review their workspace datasources and S3 configurations to ensure that sensitive credentials are not exposed. Security teams should also monitor for potential exploitation attempts.

Technical summary

CVE-2026-50136 is a vulnerability in Budibase's application server that exposes an unauthenticated endpoint for generating S3 PutObject presigned URLs. The endpoint uses credentials stored in a workspace datasource and is only protected by recaptcha middleware. An attacker with a workspace ID and S3 datasource ID can request a signed upload URL for arbitrary bucket and key values. This vulnerability has a CVSS score of 7.4 and is classified as HIGH severity. Budibase has released a patch in version 3.39.3.

Defensive priority

High priority should be given to updating Budibase to version 3.39.3 or later. Additionally, defenders should review and restrict access to workspace datasources and S3 configurations.

Recommended defensive actions

  • Update Budibase to version 3.39.3 or later
  • Review and restrict access to workspace datasources and S3 configurations
  • Monitor for potential exploitation attempts
  • Implement additional security measures such as IP whitelisting and rate limiting
  • Conduct a thorough review of Budibase configurations and datasources

Evidence notes

The CVE record and NVD detail provide information on the vulnerability and its severity. The source item URL provides additional context on the vulnerability and its impact. The reference URL from GitHub provides information on the fix and patch.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50136 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50136

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-50136 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50136

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.