CVE-2026-76581 — The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all…¶

Key facts

CVE-2026-76581 is a Critical (9.8) vulnerability: The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-76581
Severity	Critical (9.8)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-76581/

Details¶

English | 한국어

Description¶

The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 5.0.1. This is due to inconsistent and ambiguous HMAC message construction between the unauthenticated wdpsso_step1 and wdpsso_step2 AJAX actions, where step 1 signs and discloses an unseparated concatenation of the token, state, redirect, and domain values, while step 2 verifies an unseparated concatenation that omits the domain field. This makes it possible for unauthenticated attackers, on sites connected to WPMU DEV with Hub SSO enabled and mapped to an administrator, to obtain a valid HMAC from step 1 and replay it to step 2 by moving the domain value into the redirect field, resulting in an authenticated administrator session.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-76581
CVSS Score	9.8

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-76581/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-2026-76581

# 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://wpmudev.com/project/wpmu-dev-dashboard/
https://www.wordfence.com/threat-intel/vulnerabilities/id/3d4321c8-15a4-46f5-9b0e-2098a7fcfb5b?source=cve

Generated by PoC Generator on 2026-08-30T04:54:16.540745409

Frequently asked questions¶

What is CVE-2026-76581?¶

CVE-2026-76581 is a Critical (9.8) vulnerability: The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-76581?¶

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-2026-76581?¶

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.