CVE-2025-26547: My Login Logout Plugin CSRF Vulnerability

CVE-2025-26547 Overview

CVE-2025-26547 is a Cross-Site Request Forgery (CSRF) vulnerability discovered in the My Login Logout Plugin (my-loginlogout) for WordPress, developed by nagarjunsonti. This vulnerability allows attackers to exploit the CSRF weakness to inject malicious scripts, resulting in Stored Cross-Site Scripting (XSS). The attack chain leverages the absence of proper CSRF token validation to persist malicious payloads that execute in the context of authenticated users' browsers.

Critical Impact

Attackers can leverage this CSRF-to-Stored-XSS chain to hijack user sessions, deface websites, steal sensitive information, and potentially compromise administrator accounts on affected WordPress installations.

Affected Products

• My Login Logout Plugin for WordPress versions from n/a through 2.4
• WordPress installations using the vulnerable plugin versions
• Sites relying on the my-loginlogout plugin for authentication display functionality

Discovery Timeline

• 2025-02-13 - CVE-2025-26547 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-26547

Vulnerability Analysis

This vulnerability represents a chained attack pattern combining Cross-Site Request Forgery (CWE-352) with Stored Cross-Site Scripting capabilities. The My Login Logout Plugin fails to implement proper CSRF protection on critical administrative functions, allowing attackers to forge requests that inject malicious JavaScript code into the plugin's stored settings. Once the malicious payload is stored, it executes whenever the affected page elements are rendered, impacting all visitors to the compromised site.

The attack requires user interaction, specifically tricking an authenticated administrator into visiting a malicious page or clicking a crafted link. However, the impact extends beyond the initial victim since the stored XSS payload persists and affects all subsequent site visitors, creating a scope change that amplifies the security impact.

Root Cause

The root cause of this vulnerability lies in the absence of nonce verification (CSRF tokens) on form submissions within the plugin's administrative interface. WordPress provides built-in CSRF protection through its nonce system (wp_nonce_field() and wp_verify_nonce()), but the My Login Logout Plugin fails to properly implement these security controls. Additionally, the plugin does not adequately sanitize or escape user-supplied input before storing it in the database or rendering it on the frontend, enabling the stored XSS component of this attack chain.

Attack Vector

The attack is network-based and requires the attacker to craft a malicious webpage or email containing a hidden form or JavaScript that automatically submits a forged request to the vulnerable WordPress installation. The attack flow typically follows this pattern:

1. Attacker identifies a WordPress site using My Login Logout Plugin version 2.4 or earlier
2. Attacker crafts a malicious HTML page containing a hidden form targeting the plugin's settings endpoint
3. The form includes XSS payload in one of the plugin's configurable fields
4. Attacker tricks an authenticated WordPress administrator into visiting the malicious page
5. The hidden form auto-submits, and without CSRF validation, the plugin accepts the malicious settings
6. The XSS payload is stored in the WordPress database and rendered on the frontend

The attacker's malicious page would contain an auto-submitting form that targets the plugin's settings handler. Since the plugin lacks CSRF token verification, the request is processed as legitimate when made in the context of an authenticated administrator's session. The injected JavaScript payload is then stored and executed whenever the login/logout functionality is displayed to site visitors.

Detection Methods for CVE-2025-26547

Indicators of Compromise

• Unexpected JavaScript code in the My Login Logout Plugin settings or widget output
• Modified plugin settings without administrator action, particularly in login/logout display text fields
• Browser console errors indicating blocked XSS attempts if Content Security Policy is enabled
• Suspicious outbound network requests from visitor browsers to unknown domains

Detection Strategies

• Review WordPress database for unexpected script tags or JavaScript event handlers in plugin-related options (wp_options table entries related to my-loginlogout)
• Implement Web Application Firewall (WAF) rules to detect and block CSRF attacks targeting WordPress admin endpoints
• Monitor WordPress admin audit logs for settings changes made from unusual IP addresses or referrers
• Use browser-based XSS detection tools to scan rendered pages for injected script content

Monitoring Recommendations

• Enable WordPress security logging to track all administrative actions and plugin settings modifications
• Configure alerts for changes to My Login Logout Plugin settings, especially from referrers outside the WordPress admin domain
• Implement Content Security Policy headers to mitigate the impact of successful XSS injection
• Regularly scan WordPress installations with security plugins that detect stored XSS patterns

How to Mitigate CVE-2025-26547

Immediate Actions Required

• Update the My Login Logout Plugin to a patched version when available from the WordPress plugin repository
• Audit current plugin settings for any unauthorized or suspicious content, particularly JavaScript code
• Consider temporarily disabling the My Login Logout Plugin until a patched version is confirmed
• Implement Web Application Firewall rules to block potential CSRF and XSS attack patterns targeting WordPress

Patch Information

Currently, no official patch has been confirmed in the available data. WordPress site administrators should monitor the Patchstack Security Vulnerability Report for updates on remediation guidance. Until a patch is available, implementing the workarounds below is strongly recommended.

Workarounds

• Implement additional CSRF protection at the web server level using ModSecurity or similar WAF solutions with WordPress-specific rulesets
• Restrict WordPress admin access to trusted IP addresses only using .htaccess or firewall rules
• Deploy Content Security Policy headers to prevent inline script execution, mitigating the XSS impact even if CSRF succeeds
• Consider using alternative login/logout plugins that have verified CSRF protection until a patch is released

# Example: Add CSP header in Apache .htaccess to mitigate XSS impact
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';"

# Example: Restrict WordPress admin to specific IPs in .htaccess
<Files wp-admin>
    Order deny,allow
    Deny from all
    Allow from 192.168.1.0/24
</Files>