CVE-2025-26554: WP Discord Post XSS Vulnerability

CVE-2025-26554 Overview

CVE-2025-26554 is a reflected Cross-Site Scripting (XSS) vulnerability in the Nicola Mustone WP Discord Post WordPress plugin. The flaw affects all versions of wp-discord-post up to and including 2.1.0. The plugin fails to properly neutralize user-supplied input during web page generation, allowing attackers to inject arbitrary JavaScript into responses rendered by the victim's browser. The issue is classified under CWE-79 and requires user interaction to exploit, typically through a crafted link.

Critical Impact

Successful exploitation enables attackers to execute arbitrary JavaScript in a victim's browser session, leading to session hijacking, credential theft, or redirection to attacker-controlled infrastructure.

Affected Products

• Nicola Mustone WP Discord Post plugin for WordPress
• All versions from n/a through 2.1.0
• WordPress sites with the vulnerable plugin installed and active

Discovery Timeline

• 2025-03-15 - CVE-2025-26554 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-26554

Vulnerability Analysis

The vulnerability is a reflected XSS flaw in the WP Discord Post WordPress plugin. The plugin accepts input from HTTP request parameters and reflects that data back into rendered HTML responses without sufficient output encoding or sanitization. An attacker crafts a URL containing malicious JavaScript payloads in the vulnerable parameter, then convinces a victim to click the link. When the victim's browser loads the response, the injected script executes within the security context of the WordPress site.

The scope-changed CVSS vector indicates that exploitation can affect resources beyond the vulnerable component, meaning injected scripts may reach authenticated administrator sessions or other browser-accessible resources. The attack requires no authentication but does require user interaction.

Root Cause

The root cause is improper neutralization of input during web page generation [CWE-79]. The plugin code paths in version 2.1.0 and earlier echo request-derived values into HTML output without applying WordPress escaping functions such as esc_html(), esc_attr(), or wp_kses(). The lack of contextual output encoding allows HTML and JavaScript metacharacters to break out of their intended context.

Attack Vector

The attack is delivered over the network. An attacker constructs a URL targeting the vulnerable parameter in the wp-discord-post plugin and distributes it through phishing emails, malicious advertisements, or social media. When an authenticated WordPress user, especially an administrator, clicks the link, the reflected payload executes in their browser. The attacker can steal cookies, perform actions on behalf of the user, or pivot to further compromise the WordPress installation. Refer to the Patchstack advisory for technical details.

Detection Methods for CVE-2025-26554

Indicators of Compromise

• HTTP request logs containing URL parameters with encoded <script>, javascript:, or onerror= payloads targeting endpoints associated with the wp-discord-post plugin
• Unexpected outbound requests from administrator browsers to unfamiliar domains shortly after clicking external links
• WordPress audit log entries showing privileged actions originating from sessions immediately after suspicious referrer URLs

Detection Strategies

• Inspect web server access logs for requests to wp-discord-post plugin paths with suspicious query string content containing HTML or JavaScript characters
• Deploy a Web Application Firewall (WAF) rule set that flags reflected XSS patterns in query parameters targeting WordPress plugin endpoints
• Use plugin vulnerability scanners such as WPScan to identify installations running wp-discord-post version 2.1.0 or earlier

Monitoring Recommendations

• Enable Content Security Policy (CSP) reporting to capture inline script execution attempts on WordPress pages
• Monitor administrator account activity for anomalous post creation, user role changes, or plugin modifications following external link clicks
• Forward WordPress and web server logs to a centralized analytics platform to correlate phishing-delivered URLs with subsequent administrative actions

How to Mitigate CVE-2025-26554

Immediate Actions Required

• Identify all WordPress sites running the wp-discord-post plugin and confirm the installed version
• Deactivate and remove the plugin on any site running version 2.1.0 or earlier until a patched release is available
• Rotate WordPress administrator passwords and invalidate active sessions if exploitation is suspected

Patch Information

At the time of NVD publication, no fixed version is listed for WP Discord Post. The vulnerability affects all versions up to and including 2.1.0. Administrators should consult the Patchstack advisory for the latest remediation status and apply any vendor-supplied update as soon as it is released.

Workarounds

• Remove or deactivate the wp-discord-post plugin until an official patch is published
• Deploy a Web Application Firewall rule that blocks requests containing script tags or JavaScript URI schemes in query parameters directed at the plugin
• Enforce a strict Content Security Policy on the WordPress site to prevent execution of inline and untrusted scripts
• Train administrators to avoid clicking unsolicited links pointing to their own WordPress domains

# Configuration example: deactivate the vulnerable plugin via WP-CLI
wp plugin deactivate wp-discord-post
wp plugin delete wp-discord-post