CVE-2026-5696 in Microweber
Summary
by MITRE • 09/23/2026
Reflected Cross-Site Scripting (XSS) in Microweber. The vulnerability lies in the ‘group’ parameter of the ‘/admin/settings’ endpoint in the administration panel. A successful exploit allows an attacker to trick an authenticated user into executing malicious JavaScript code in their browser. This enables the attacker to perform actions without the victim’s consent, steal confidential information or hijack the user’s session.
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Analysis
by VulDB Data Team • 09/23/2026
The vulnerability identified as a reflected Cross-Site Scripting flaw within Microweber represents a significant security risk for web applications relying on this content management system. The specific point of failure is located in the group parameter associated with the /admin/settings endpoint, which serves as a critical configuration interface for authenticated administrators. Reflected XSS occurs when malicious script code provided by an attacker is immediately returned to the user's browser without proper sanitization or encoding by the server-side application logic. In this context, the vulnerability allows an adversary to inject executable JavaScript payloads directly into HTTP responses generated in reaction to crafted requests targeting the administration panel settings page.
The technical mechanism of exploitation relies on social engineering tactics combined with precise request manipulation. An attacker constructs a malicious URL containing the injected script within the group parameter and lures an authenticated administrator or user with elevated privileges to visit this link, often through phishing emails or deceptive links embedded in other web content. Upon accessing the endpoint, the Microweber application processes the input but fails to adequately validate or escape special characters before rendering them back into the HTML response. Consequently, when the victim's browser parses the page, it interprets the injected code as legitimate script and executes it within the security context of the administration panel domain.
The operational impact of this vulnerability is severe due to the privileged nature of the target endpoint. Since the attack vector targets an administrative interface, successful exploitation grants the attacker full control over the victim's session state. This capability allows for comprehensive account takeover scenarios where the adversary can perform actions on behalf of the administrator without consent or knowledge. Specific consequences include the theft of sensitive configuration data, modification of site settings to deface content or redirect traffic, and potentially further lateral movement within the network if administrative credentials are harvested. The ability to hijack sessions also facilitates persistent access as attackers may install backdoors or modify authentication mechanisms to maintain long-term control over the compromised system.
From a classification perspective, this vulnerability aligns with CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. The attack methodology corresponds to MITRE ATT&CK technique T1059, specifically sub-technique 007 for JavaScript execution, and falls under the broader category of Client-Side Attacks such as T1053 which involves Scheduled Tasks or Jobs if persistence is established via stored scripts. Understanding these mappings helps in aligning remediation efforts with industry-standard security frameworks to ensure robust defense strategies are implemented.
Mitigation requires a multi-layered approach focusing on input validation and output encoding at the application level. Developers must implement strict whitelisting for allowed characters in the group parameter rather than relying solely on blacklists of dangerous inputs, as blacklist approaches often miss novel or encoded attack vectors. Furthermore, all dynamic content rendered to the browser must be properly HTML-encoded using context-aware escaping techniques that neutralize special characters such as angle brackets and quotes before they are inserted into the DOM. Implementing a Content Security Policy header with strict directives can also significantly reduce the impact by preventing unauthorized script execution even if injection occurs. Additionally, enabling HttpOnly flags on session cookies prevents client-side scripts from accessing sensitive cookie data, thereby mitigating session hijacking risks associated with this vulnerability type.