CVE-2026-72859

Budibase 3.39.4 before 3.40.0 Authorization Regression via S3 Presigned URL

HIGH
7.7
CVSS Score
Published: August 14, 2026 at 11:35 AM UTC
Updated: October 8, 2026 at 04:17 PM UTC
1 product affected across 1 vendorBudibase

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Severity
HIGH7.7
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

Budibase versions 3.39.4 before 3.40.0 contain an authorization regression in the S3 attachment upload endpoint that allows BASIC users to obtain S3 PutObject presigned URLs by sending POST requests to the attachments endpoint. The route was changed from a BUILDER permission check to a TABLE/WRITE check, which BASIC users hold by default. Attackers can specify arbitrary S3 buckets in the request body to generate presigned URLs for writing to any bucket accessible by the stored IAM credentials, enabling unauthorized file uploads.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.39.4 ≤ v < 3.40.03.39.4
Vendor states this is fixed in 3.40.0 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-863

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