CVE-2026-59662 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 “nomCompetidor” parameter is affected – endpoint “/es/competitors/store”.
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Analysis
by VulDB Data Team • 10/02/2026
The identified security flaw represents a classic Cross-Site Scripting (XSS) vulnerability within the Repasat web application, specifically targeting the user input handling mechanisms associated with competitor data management. This type of vulnerability arises when an application includes untrusted data in a new web page without proper validation or escaping, allowing malicious scripts to execute in the context of the victim's browser. In this specific instance, the flaw is located within the "nomCompetidor" parameter, which appears to be used for storing competitor names or identifiers via the endpoint "/es/competitors/store". The presence of this vulnerability indicates that the server-side processing does not adequately sanitize user-supplied input before it is reflected back in subsequent HTTP responses or stored for later retrieval and display.
From a technical perspective, the exploitation vector involves an attacker crafting a malicious payload containing JavaScript code or other executable script tags within the "nomCompetidor" field. When this data is submitted to the "/es/competitors/store" endpoint, it is accepted by the application without sufficient filtering of special characters such as angle brackets, quotes, and ampersands that are necessary for HTML parsing. Consequently, when another user or an administrator views the stored competitor information, the browser interprets the injected script as legitimate content belonging to the domain. This allows the attacker's code to run with the same privileges as any other script on the page, effectively bypassing the Same Origin Policy which normally prevents malicious scripts from accessing data from different domains.
The operational impact of this vulnerability is significant due to its potential for session hijacking and credential theft. An attacker can leverage this flaw to steal sensitive information such as authentication cookies, session tokens, or personally identifiable information displayed on the page. By redirecting the victim's browser to a malicious server controlled by the attacker, the stolen data can be exfiltrated in real-time. Furthermore, if the application is used for administrative purposes, an attacker could perform actions on behalf of the user, such as modifying competitor records, deleting entries, or changing configuration settings. This undermines the integrity and confidentiality of the application's data while potentially leading to broader system compromise if combined with other vulnerabilities like Cross-Site Request Forgery (CSRF).
This vulnerability aligns closely with CWE-79, which classifies Improper Neutralization of Input During Web Page Generation known as 'Cross-site Scripting'. It also maps to specific techniques within the MITRE ATT&CK framework, particularly T1059.007 for JavaScript execution and potentially T1213 if used for data exfiltration through web browsers. The lack of input validation at both client-side and server-level endpoints highlights a fundamental gap in the application's security architecture regarding secure coding practices.
To mitigate this risk, immediate remediation steps must focus on implementing robust output encoding and input validation strategies. Developers should ensure that all user-supplied data is encoded according to its context within HTML pages, using libraries designed for escaping special characters such as <, >, &, ", and '. Additionally, the implementation of Content Security Policy (CSP) headers can significantly reduce the impact of XSS attacks by restricting the sources from which scripts are allowed to load. Input validation should be enforced on both the client side for user experience and strictly on the server side at the "/es/competitors/store" endpoint to reject any input containing malicious patterns or unexpected character sets. Regular security testing, including static application security testing (SAST) and dynamic application security testing (DAST), is recommended to identify similar flaws across other parameters and endpoints within the Repasat application ecosystem.