NVD / CVE Program· CNA GitHub_M

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

Noroxi assessment

Priority: Monitor (action score 21/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.29% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Budibase budibase 3.39.3.
Severity is disputed: the assigning authority (CNA) scores it 7.4, NVD 5.3.

Low priority for now. Upgrade to Budibase budibase 3.39.3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.3 · v3.1—No exploit Fix available

GHSA-jj36-r9w3-3pfh

Published: Jun 26, 2026
Updated: Jun 30, 2026
EPSS: 0.2% · 21th percentile
CWE: CWE-306

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 21 / 40 · 5.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: proof of concept
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 5.3
CNA · GitHub_M: 7.4; 2.1 point gap

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
budibase	budibase	cpe:2.3:a:budibase:budibase

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

budibase budibasebefore 3.39.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

Budibase budibase
- < 3.39.3affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
npm	@budibase/server	before 3.39.2	3.39.2

Same product

budibase: all records

Other highest-scoring records for the same primary product.

CVE-2026-31816Budibase Universal Auth Bypass via Webhook Query Param Injection
41Plan
CVE-2026-54350Budibase: Anonymous NoSQL operator injection via published-app query templates
39Monitor
CVE-2026-46425Budibase: SCIM endpoints lack role-based authorization, BASIC users CRUD tenant users
39Monitor

Published before and after this one in the same product

← EarlierCVE-2026-48153May 27, 2026 · Budibase: SSRF via OAuth2 token endpoint URL reaches internal hosts and cloud metadata
34Monitor
← EarlierCVE-2026-50132Jun 26, 2026 · Budibase: Chat Identity Link Hijacking via Missing Consent & CSRF — Account Impersonation in Budibase
29Monitor
Later →CVE-2026-50137Jun 26, 2026 · Budibase: POST /api/attachments/:datasourceId/url is unauthenticated and lets anonymous callers mint S3 PUT pre-signed URLs using stored datasource IAM credenti
32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Budibase budibase	3.39.3 · description	Vendor (CNA)
npm:@budibase/server	3.39.2	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2026-543520 days apartBudibase: Arbitrary file read by workspace-builder via PWA-zip symlink upload
38Monitor
CVE-2026-4571730 days apartBudibase: `PUT /api/datasources/:datasourceId` is protected only by `TABLE/READ` permission instead of builder access, allowing any authenticated app user to ov
35Monitor
CVE-2026-4815330 days apartBudibase: SSRF via OAuth2 token endpoint URL reaches internal hosts and cloud metadata
34Monitor
CVE-2026-543530 days apartBudibase: Potential SSRF DNS rebinding bypass in outbound fetch validation
28Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: low · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: Low
Availability impact: None

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

nvd-primary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

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