CVE-2026-59669 in Repasat
Summary
by MITRE • 10/02/2026
Cross-Site Scripting vulnerability in the Repasat application. Successful exploitation of this vulnerability could allow an attacker to trick a user into executing arbitrary code in the victim’s browser. The “name” parameter is affected – endpoint “/es/attachmenttypes/update/203336”
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Analysis
by VulDB Data Team • 10/02/2026
The identified Cross-Site Scripting (XSS) vulnerability within the Repasat application represents a significant security flaw that compromises the integrity and confidentiality of user interactions. This specific weakness resides in the handling of input data for the name parameter, which is processed via the endpoint /es/attachmenttypes/update/203336. The core technical issue stems from insufficient validation or sanitization of user-supplied content before it is rendered back to the client browser. When an attacker crafts a malicious payload containing executable JavaScript code and injects it into this parameter, the application fails to neutralize these scripts. Consequently, when another user accesses the affected page where this data is displayed, their browser interprets the injected script as legitimate content originating from the trusted domain of Repasat. This mechanism allows for Stored XSS if the input is persisted in a database or reflected XSS if it is immediately rendered without proper encoding, both of which facilitate the execution of arbitrary code within the context of the victim's session.
The operational impact of this vulnerability extends beyond simple script execution to severe compromises of user privacy and application security posture. By successfully exploiting this flaw, an attacker can perform a variety of malicious actions on behalf of the victim. These include stealing sensitive session cookies or authentication tokens, which could lead to account takeover attacks where the adversary assumes full control over the victim's identity within the Repasat system. Furthermore, the attacker may manipulate the DOM (Document Object Model) to alter page content, redirect users to phishing sites designed to harvest credentials, or keylog keystrokes entered into forms on the application. This undermines user trust and exposes the organization to potential data breaches, regulatory non-compliance, and reputational damage due to the perceived lack of security controls over user input handling mechanisms.
From a classification perspective, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting. The specific vector involves the injection of executable scripts through an HTTP parameter that is subsequently rendered without adequate sanitization. In terms of offensive security frameworks such as MITRE ATT&CK, this exploitation technique falls under T1059: Command and Control via Application Layer Protocol or more specifically relates to techniques involving client-side code execution like T1071: Application Layer Protocol for C2 communications if used for beaconing, but primarily it facilitates initial access and credential harvesting which are foundational steps in many attack chains. The lack of output encoding allows the malicious payload to bypass standard browser security policies that rely on same-origin assumptions, effectively breaking the isolation between different web applications or domains running within the user's environment.
To mitigate this vulnerability, immediate remediation efforts must focus on implementing robust input validation and strict output encoding strategies. Developers should enforce a whitelist approach for allowed characters in the name parameter to reject any unexpected symbols such as angle brackets, quotes, or ampersands that are commonly used in XSS payloads. Additionally, all user-supplied data rendered into HTML contexts must be properly encoded using context-aware techniques; for instance, HTML entity encoding for general text content and JavaScript escaping if the data is embedded within script blocks. Implementing a Content Security Policy (CSP) header with strict directives can also serve as an effective defense-in-depth measure by restricting the sources from which scripts are allowed to execute, thereby neutralizing many XSS attacks even if input validation fails. Regular security testing using both static and dynamic analysis tools should be integrated into the development lifecycle to detect such flaws early before deployment to production environments.