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CVE-2026-15013 — The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication…

Key facts

CVE-2026-15013 is a Critical (9.8) vulnerability: The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication…. This entry ships a detection-only PoC and a Docker test lab.

CVE CVE-2026-15013
Severity Critical (9.8)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-15013/

Details

English | 한국어

Description

The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication Bypass via SAML Signature Algorithm Confusion in all versions up to, and including, 5.4.3. The vulnerability exists because Mo_SAML_Utilities::mo_saml_cast_key() reads the SignatureMethod Algorithm attribute directly from the attacker-controlled SAMLResponse parameter rather than enforcing the locally configured algorithm, causing the plugin to recast the IdP's RSA public key as an HMAC-SHA1 shared secret and validate the forged signature against it. This makes it possible for unauthenticated attackers to forge a SAML assertion targeting any WordPress account — including administrators — obtain valid WordPress authentication cookies, and achieve full administrator-level account takeover.

Vulnerability Details

Property Value
CVE ID CVE-2026-15013
CVSS Score 9.8

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-15013/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-2026-15013

# 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://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo-saml-login-validate.php#L119
  • https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo-saml-utilities.php#L416
  • https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo-saml-utilities.php#L444
  • https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo-saml-utilities.php#L561
  • https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/includes/lib/SAML2Core/class-mo-saml-xml-security-key.php#L722
  • https://plugins.trac.wordpress.org/changeset?reponame=&old=3601345%40miniorange-saml-20-single-sign-on&new=3601345%40miniorange-saml-20-single-sign-on
  • https://www.wordfence.com/threat-intel/vulnerabilities/id/ee95092d-6351-4612-872d-284165bc1201?source=cve

Generated by PoC Generator on 2026-07-16T16:08:14.470118366

Frequently asked questions

What is CVE-2026-15013?

CVE-2026-15013 is a Critical (9.8) vulnerability: The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-15013?

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-2026-15013?

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.