CVE-2026-72859

Budibase 3.39.4 before 3.40.0 Authorization Regression via S3 Presigned URL

Published Aug 14, 2026 CVSS 4.0 · 8.3 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Budibase server
Vendors & Products Budibase server
Type Values Removed Values Added
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.
Title Budibase 3.39.4 before 3.40.0 Authorization Regression via S3 Presigned URL
First Time appeared Budibase
Budibase budibase
Weaknesses CWE-863
CPEs cpe:2.3:a:budibase:budibase:*:*:*:*:*:*:*:*
Vendors & Products Budibase
Budibase budibase
References
Metrics cvssV3_1

{'score': 7.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N'}

cvssV4_0

{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 8, 2026, 3:24 PM
Reserved
Aug 10, 2026, 3:16 PM
Status
Deferred
Published
Aug 14, 2026, 12:16 PM
Modified
Oct 8, 2026, 4:17 PM