CVE-2025-28869 Overview
CVE-2025-28869 is a reflected Cross-Site Scripting (XSS) vulnerability in the NextGEN Gallery Voting WordPress plugin developed by shauno. The flaw affects all plugin versions up to and including 2.7.6. It stems from improper neutralization of user-supplied input during web page generation, classified under [CWE-79]. An unauthenticated attacker can craft a malicious URL that, when clicked by a victim, executes arbitrary JavaScript in the victim's browser session. The scope is changed (S:C), meaning impact extends beyond the vulnerable component to other resources within the WordPress site.
Critical Impact
Attackers can hijack authenticated sessions, steal cookies, perform actions on behalf of administrators, and deliver further payloads through crafted links.
Affected Products
- shauno NextGEN Gallery Voting plugin for WordPress
- All versions from n/a through 2.7.6
- WordPress sites running the nextgen-gallery-voting plugin
Discovery Timeline
- 2025-03-26 - CVE-2025-28869 published to NVD
- 2026-04-23 - Last updated in NVD database
Technical Details for CVE-2025-28869
Vulnerability Analysis
The vulnerability resides in the NextGEN Gallery Voting plugin's handling of HTTP request parameters. The plugin reflects user-controlled input back into the rendered HTML response without applying proper output encoding or input sanitization. When a victim follows a crafted link, the injected script executes in the context of the WordPress origin.
Because the CVSS scope is changed, script execution can affect resources beyond the plugin itself, including the broader WordPress administrative interface. Successful exploitation yields limited but meaningful impact across confidentiality, integrity, and availability. The attack requires user interaction, typically through phishing or social engineering. Authentication is not required to deliver the payload.
Root Cause
The root cause is the absence of contextual output escaping on parameters reflected into plugin-generated pages. WordPress provides sanitization helpers such as esc_html(), esc_attr(), and esc_url() for this purpose. The vulnerable plugin code paths emit attacker-controlled values directly into HTML contexts without invoking these helpers, allowing <script> tags or event handler attributes to break out of the intended data context.
Attack Vector
Exploitation occurs over the network through a crafted URL containing the malicious payload in a vulnerable parameter. The attacker distributes the link through email, chat, or a malicious site. When a logged-in WordPress user, especially an administrator, opens the link, the reflected payload executes. Typical post-exploitation activities include session token theft, forced administrative actions through CSRF chains, credential harvesting via injected forms, and redirection to malware distribution domains.
For technical details on the affected parameter and payload structure, refer to the Patchstack Vulnerability Analysis.
Detection Methods for CVE-2025-28869
Indicators of Compromise
- HTTP requests to nextgen-gallery-voting endpoints containing URL-encoded <script>, onerror=, onload=, or javascript: substrings.
- Web server access logs showing query strings with reflected HTML metacharacters such as %3C, %3E, and %22.
- Unexpected outbound connections from administrator browser sessions to attacker-controlled domains following plugin page visits.
Detection Strategies
- Inspect WordPress access logs for requests to plugin URLs containing encoded script tags or JavaScript URI schemes.
- Deploy a Web Application Firewall (WAF) rule set targeting reflected XSS patterns on plugin parameters.
- Correlate referrer headers from external domains with subsequent administrator account activity to identify phishing-driven exploitation.
Monitoring Recommendations
- Enable WordPress audit logging to track administrator-level configuration changes following plugin page access.
- Monitor for new or modified administrative users, plugin installations, and theme edits as post-exploitation indicators.
- Alert on browser console errors and Content Security Policy violations reported by CSP report-uri endpoints.
How to Mitigate CVE-2025-28869
Immediate Actions Required
- Identify all WordPress installations running the nextgen-gallery-voting plugin at version 2.7.6 or earlier.
- Deactivate the plugin until a vendor-patched release is verified and deployed.
- Force-rotate administrator session cookies and reset privileged credentials if exploitation is suspected.
- Apply WAF signatures that block reflected XSS payloads against the plugin's URL paths.
Patch Information
At the time of NVD publication, the vulnerability affects NextGEN Gallery Voting versions through 2.7.6 with no fixed version listed. Site operators should monitor the Patchstack advisory and the WordPress plugin repository for an updated release, and apply it immediately upon availability.
Workarounds
- Remove or disable the NextGEN Gallery Voting plugin where its functionality is non-essential.
- Implement a strict Content Security Policy (CSP) that disallows inline scripts and untrusted script sources to limit payload execution.
- Restrict access to WordPress administrative pages by IP allowlist to reduce administrator exposure to phishing links.
- Train administrators to avoid following untrusted links into authenticated WordPress sessions.
# Example: disable the vulnerable plugin via WP-CLI
wp plugin deactivate nextgen-gallery-voting
wp plugin status nextgen-gallery-voting
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
