CVE-2026-14911 in ASUS
Summary
by MITRE • 10/07/2026
Improper Neutralization of Input During Web Page Generation (“Cross-site Scripting”) in ASUS router modules allows a remote attacker to read DOM information, modify router settings, and cause a denial-of-service condition when an authenticated user visits a crafted URL.Refer to the ' Security Update for ASUS Router Firmware ' section on the ASUS Security Advisory for more information.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability described constitutes a classic instance of Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting or XSS. This flaw resides within the web interface modules of specific ASUS router firmware versions and represents a significant security deficiency in how user-supplied data is processed before being rendered to the client browser. The core technical issue stems from the application's failure to adequately sanitize or encode special characters, such as HTML tags, JavaScript event handlers, and other executable script fragments, within input fields that are subsequently reflected back into the web page without proper validation. When an authenticated user interacts with a crafted URL containing maliciously constructed parameters, the router’s web server processes these inputs and embeds them directly into the Document Object Model (DOM) of the response page. Because the browser interprets this content as executable code rather than inert data, it executes the injected scripts in the context of the trusted ASUS administration interface.
The operational impact of this vulnerability is severe due to the privileged nature of the authenticated session. Since the attack requires prior authentication, an attacker who has obtained valid credentials or exploited a separate credential-based weakness can leverage this XSS flaw to perform actions that are typically restricted to administrators. The primary consequence is the ability to read sensitive DOM information, which may include internal network configurations, connected device details, and potentially stored administrative tokens or session cookies if they are accessible via client-side scripts. Furthermore, the attacker can modify router settings dynamically by injecting JavaScript commands that interact with the web interface's API endpoints. This capability allows for unauthorized changes to DNS settings, firewall rules, port forwarding configurations, and other critical network parameters without requiring a full re-authentication cycle in many implementations.
Beyond configuration tampering, this vulnerability enables a denial-of-service condition against the router’s management plane or connected clients. By injecting scripts that trigger infinite loops, excessive DOM manipulations, or continuous requests to internal services, an attacker can degrade the performance of the web interface or exhaust system resources on client devices accessing the network through the compromised router. This effectively disrupts normal administrative operations and can lead to a complete unavailability of remote management capabilities for legitimate users. The attack vector is primarily passive in terms of initial delivery but active once executed; it relies on social engineering or phishing tactics where an authenticated user, such as a system administrator or a home network owner, is tricked into visiting the malicious URL while logged into their router’s administrative panel.
From a classification perspective, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation (Cross-site Scripting). It also maps to MITRE ATT&CK techniques related to Client-Side Injection and potentially Command and Control if used for persistent access or data exfiltration via the compromised session. The requirement for authentication places this within the scope of authenticated attacks, which are often more dangerous than unauthenticated ones because they bypass initial perimeter defenses that rely on anonymous access controls.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary solution is to apply the security update provided by ASUS as detailed in their official Security Advisory for Router Firmware. This patch likely includes input validation routines, output encoding mechanisms, and potentially the implementation of Content Security Policy headers to restrict script execution contexts. Administrators should ensure that firmware updates are applied promptly upon release from vendors who maintain a track record of timely security patches. Additionally, implementing strict access controls is critical; administrative interfaces should be restricted to trusted IP addresses or VPN connections where possible to reduce the attack surface for credential theft and subsequent exploitation. Users must also exercise caution when clicking links within their own management consoles, as this vulnerability exploits trust in the interface itself rather than just external network traffic. Regular auditing of router configurations and monitoring for unusual outbound traffic can help detect potential compromise resulting from such an exploit before significant damage occurs.