CVE-2026-59659 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 “nomZonaGeo” parameter is affected – endpoint “/es/geozones/update/149979”.
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Analysis
by VulDB Data Team • 10/02/2026
The Repasat application contains a Cross-Site Scripting vulnerability within its geolocation management interface, specifically targeting the nomZonaGeo parameter at the /es/geozones/update/149979 endpoint. This flaw represents a classic instance of reflected or stored cross-site scripting where user-supplied input is not adequately sanitized before being processed by the server and subsequently rendered in the victim's browser context. The vulnerability arises from insufficient validation mechanisms that fail to filter out malicious script payloads embedded within the geographic zone name field, allowing an attacker to inject executable JavaScript code directly into the application’s response stream.
From a technical perspective, this deficiency aligns with CWE-79, which classifies improper neutralization of input during web page generation as a critical security weakness. When a user interacts with the affected endpoint, the server accepts the malicious payload without encoding special characters such as angle brackets or quotation marks that are essential for breaking out of HTML contexts. Consequently, when the response is rendered in the client’s browser, the injected script executes within the same origin context as the legitimate application code. This bypasses standard security controls like Same-Origin Policy because the browser treats the malicious content as trusted source material originating from the Repasat domain itself rather than an external third party.
The operational impact of this vulnerability is significant due to its potential for session hijacking and data exfiltration. An attacker can craft a deceptive link or embed the payload in a phishing email, tricking an authenticated user into clicking it while logged into their account. Once executed, the arbitrary code runs with the privileges of that specific user, enabling the theft of sensitive cookies, session tokens, and authentication credentials. Furthermore, the attacker could manipulate the DOM to alter application behavior, redirect users to malicious sites designed for credential harvesting, or perform actions on behalf of the victim without authorization. This effectively compromises the confidentiality and integrity of the system by allowing unauthorized access to protected resources and user data.
This attack vector is consistent with MITRE ATT&CK technique T1059, which covers command and script interpretation through browser-based execution, often categorized under Initial Access or Credential Access depending on the specific payload intent. The exploitation relies heavily on social engineering elements where trust in the application’s interface is abused to lower user vigilance regarding suspicious links or inputs.
To mitigate this vulnerability, immediate remediation efforts should focus on implementing robust input validation and output encoding strategies at both the client and server levels. Developers must enforce strict allow-listing for the nomZonaGeo parameter, ensuring that only expected alphanumeric characters and safe punctuation are accepted while rejecting any HTML tags or script-like syntax. Additionally, applying context-sensitive output encoding is critical to ensure that special characters are properly escaped before being rendered in the browser, thereby neutralizing their executable potential. Deploying a Web Application Firewall can also provide an additional layer of defense by detecting and blocking known XSS patterns in HTTP traffic. Regular security testing including dynamic application security scanning should be integrated into the development lifecycle to identify similar flaws across other endpoints within the Repasat ecosystem before they can be exploited in production environments.