CVE-2026-100623 — Capgo (capgo.app) exposes the legacy membership table public.org_users directly through…¶

Key facts

CVE-2026-100623 is a High (8.8) vulnerability: Capgo (capgo.app) exposes the legacy membership table public.org_users directly through…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-100623
Severity	High (8.8)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-100623/

Details¶

English | 한국어

Description¶

Capgo (capgo.app) exposes the legacy membership table public.org_users directly through Supabase PostgREST. The table's row-level security policies "Allow org admin to insert" and "Allow org admin to update" only verify that the caller has admin rights in the target organization (public.check_min_rights('admin', ...)); they do not require a pending invitation in tmp_users, acceptance of an invite token via /private/accept_invitation, any action by the target user, or the membership/role-consistency and anti-escalation checks enforced by the RBAC role-binding path. As a result, an authenticated user who is an admin of an organization can INSERT or UPDATE org_users rows directly to add any existing public.users account as an active member of that organization with user_right="admin", bypassing the invitation and role-assignment workflow entirely. In testing, an account with no prior access to the organization or its apps could, after such a direct insert, read the organization and app and pass check_min_rights. All versions are affected and no patch was available at the time of publication.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-100623
Type	RCE
CVSS Score	8.8

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-100623/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-2026-100623

# 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/Cap-go/capgo.app/security/advisories/GHSA-w349-9mc3-8c5x
https://www.vulncheck.com/advisories/capgo-authentication-bypass-via-direct-postgrest-org-users-table-write

Generated by PoC Generator on 2026-09-27T05:02:53.554413607

Frequently asked questions¶

What is CVE-2026-100623?¶

CVE-2026-100623 is a High (8.8) vulnerability: Capgo (capgo.app) exposes the legacy membership table public.org_users directly through…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-100623?¶

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-2026-100623?¶

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.