CVE-2026-5725 in Favicon Rotator Plugin
Summary
by MITRE • 10/10/2026
The Favicon Rotator plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'fvrt_' prefixed request parameters in all versions up to, and including, 1.2.11 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 10/10/2026
The Favicon Rotator plugin, widely utilized within the WordPress ecosystem to dynamically change site icons based on time or other triggers, contains a critical security flaw identified across all versions up to and including 1.2.11. This vulnerability manifests as a Reflected Cross-Site Scripting (XSS) issue rooted in insufficient input sanitization and output escaping mechanisms. The attack vector is specifically tied to request parameters prefixed with fvrt_, which are processed by the plugin without adequate validation against malicious payloads. Because the flaw resides in how user-supplied data is handled before being rendered back into the HTTP response, it allows for direct injection of executable client-side scripts into web pages viewed by legitimate users.
From a technical perspective, this vulnerability aligns with CWE-79, which classifies improper neutralization of input during web page generation as Cross-site Scripting. The core issue lies in the application's failure to properly encode or sanitize data retrieved from HTTP request parameters before embedding it into HTML output. When an attacker crafts a malicious URL containing script tags or event handlers within these fvrt_ prefixed parameters, and subsequently tricks a victim into accessing that link, the browser interprets the injected content as part of the page structure rather than plain text. This lack of context-aware escaping means that any JavaScript code included in the payload will execute with the same privileges as the rest of the webpage, effectively bypassing standard security controls like Content Security Policy if not strictly configured to block inline scripts.
The operational impact of this reflected XSS vulnerability is significant for both end-users and site administrators. Since authentication is not required to exploit this flaw, any unauthenticated attacker can generate a malicious link that targets users visiting the affected WordPress site. Successful exploitation allows attackers to steal session cookies, hijack user sessions, perform actions on behalf of authenticated users such as changing passwords or publishing content, and redirect victims to phishing sites designed to harvest credentials. In environments where administrative accounts frequently access the dashboard via shared links or bookmarks containing these parameters, the risk escalates further, potentially leading to full site compromise if combined with other vulnerabilities like CSRF token bypasses.
This vulnerability is also mapped to MITRE ATT&CK technique T1059.007, which covers JavaScript execution as a method for client-side code injection. The attack pattern typically involves social engineering tactics where the attacker distributes the crafted URL through email, instant messaging, or other channels to lure victims into clicking it. Once clicked, the malicious script executes in the victim's browser context, enabling data exfiltration or further lateral movement within the application environment. The reflected nature of this XSS means that persistent storage is not required for exploitation, making it particularly dangerous as a vector for targeted attacks against specific individuals rather than broad-scale automated campaigns.
To mitigate this vulnerability, immediate action must be taken by updating the Favicon Rotator plugin to version 1.2.12 or later, where these input handling flaws have been addressed through rigorous sanitization and output encoding practices. Site administrators should also implement a Web Application Firewall (WAF) configured with rules specifically targeting reflected XSS patterns involving query parameters containing script-like syntax. Additionally, enforcing strict Content Security Policy headers can help mitigate the impact of any successful injection by restricting the sources from which scripts are allowed to execute. Regular security audits and code reviews focusing on input validation and output encoding standards such as OWASP's guidelines for preventing cross-site scripting should be conducted to ensure long-term resilience against similar attack vectors in WordPress plugins and custom themes alike.