CVE-2026-100684 — Budibase versions 3.41.0 before 3.45.0 contain an authentication bypass in the OIDC/SSO…¶

Key facts

CVE-2026-100684 is a High (8.1) vulnerability: Budibase versions 3.41.0 before 3.45.0 contain an authentication bypass in the OIDC/SSO…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-100684
Severity	High (8.1)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-100684/

Details¶

English | 한국어

Description¶

Budibase versions 3.41.0 before 3.45.0 contain an authentication bypass in the OIDC/SSO login path of @budibase/server. In sso.authenticate, when no existing user matches the incoming SSO subject, the server looks up pending user invites by the IdP-asserted email address alone — without validating an invite code and without an email_verified check (the email_verified gate protects only the existing-account lookup). An attacker who can register at an IdP that the tenant trusts for OIDC and assert a victim's invited email address (even with email_verified=false) claims the pending invite and inherits all of its granted privileges, including builder and admin.global, with no admin exclusion. This results in takeover of the invited principal and, for admin invites, full tenant compromise (access to all apps, datasources including production credentials, and automations); the invite is consumed, denying onboarding to the legitimate invitee.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-100684
Type	RCE
CVSS Score	8.1

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-100684/poc.py

Usage¶

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab¶

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start¶

# Clone and navigate to CVE directory
cd CVE-2026-100684

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints¶

Application	URL	Status
Vulnerable App	http://localhost:8080	Shows vulnerability
Patched App	http://localhost:8081	Demonstrates fix

Directory Structure¶

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References¶

https://github.com/Budibase/budibase/security/advisories/GHSA-35ch-57g2-3g98
https://www.vulncheck.com/advisories/budibase-server-3.41.0-before-3.45.0-authentication-bypass-via-oidc

Generated by PoC Generator on 2026-09-27T01:16:43.359051528

Frequently asked questions¶

What is CVE-2026-100684?¶

CVE-2026-100684 is a High (8.1) vulnerability: Budibase versions 3.41.0 before 3.45.0 contain an authentication bypass in the OIDC/SSO…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-100684?¶

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2026-100684?¶

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

For authorized security testing and research only. See the full source and NVD record.