CVE-2025-58874 is a medium-severity vulnerability classified under CWE-79, indicating an improper neutralization of input during web page generation, commonly known as Cross-site Scripting (XSS). Specifically, this vulnerability affects the josepsitjar StoryMap product up to version 2.1. The flaw is a DOM-based XSS, meaning that the malicious script is executed as a result of modifying the Document Object Model (DOM) environment in the victim's browser, rather than being directly injected into the HTML response from the server. This type of XSS occurs when client-side scripts process untrusted data insecurely, allowing attackers to execute arbitrary JavaScript in the context of the affected web application. The CVSS v3.1 score of 6.5 reflects a medium severity, with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), scope changed (S:C), and impacts on confidentiality, integrity, and availability all rated low (C:L/I:L/A:L). The vulnerability allows an attacker with some level of privileges and requiring user interaction to execute scripts that can steal sensitive information, manipulate the user interface, or perform actions on behalf of the user. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability is significant because StoryMap is a tool used for creating interactive maps and storytelling applications, often embedded in websites or intranets, which may be used by organizations to present geospatial or narrative content. Improper input handling in such applications can lead to session hijacking, data theft, or unauthorized actions within the user's browser context.

For European organizations using josepsitjar StoryMap, this vulnerability poses risks primarily to confidentiality and integrity of user data and sessions. Attackers exploiting this DOM-based XSS could hijack user sessions, steal authentication tokens, or manipulate displayed content, potentially leading to misinformation or unauthorized actions. Given that StoryMap is often used for public-facing or internal communication platforms, exploitation could damage organizational reputation, lead to data breaches, or facilitate further attacks within the network. The requirement for user interaction and some privilege level reduces the risk somewhat but does not eliminate it, especially in environments where users have elevated privileges or where social engineering could induce interaction. The scope change in the CVSS vector indicates that exploitation could affect resources beyond the initially vulnerable component, potentially impacting other parts of the application or integrated systems. European organizations in sectors such as government, education, cultural institutions, and media that utilize StoryMap for interactive content are particularly at risk. Additionally, regulatory frameworks like GDPR impose strict requirements on protecting personal data, so exploitation leading to data leakage could result in legal and financial consequences.

To mitigate this vulnerability, organizations should first monitor for official patches or updates from the josepsitjar vendor and apply them promptly once available. In the absence of patches, organizations can implement strict Content Security Policies (CSP) to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. Input validation and sanitization should be enforced on all user-supplied data processed by StoryMap, especially data that influences the DOM. Employing frameworks or libraries that automatically encode or escape output can help prevent injection of malicious scripts. Additionally, organizations should educate users about the risks of interacting with untrusted content and implement multi-factor authentication to reduce the impact of session hijacking. Regular security assessments and penetration testing focusing on client-side vulnerabilities can help identify and remediate similar issues. Logging and monitoring for unusual user behavior or script execution anomalies can aid in early detection of exploitation attempts. Finally, isolating StoryMap instances in segmented network zones can limit lateral movement if an attack occurs.