CVE-2025-24764 is a DOM-Based Cross-Site Scripting (XSS) vulnerability classified under CWE-79, which involves improper neutralization of input during web page generation. This vulnerability affects the product '(Simply) Guest Author Name' developed by A. Jones, specifically versions up to 4.36. DOM-Based XSS occurs when client-side scripts write user-controllable data to the Document Object Model (DOM) without proper sanitization or encoding, enabling attackers to execute arbitrary JavaScript in the context of the victim's browser. The vulnerability allows an attacker with at least low privileges (PR:L) and requiring user interaction (UI:R) to exploit the flaw remotely (AV:N) with low attack complexity (AC:L). The scope is changed (S:C), indicating that the vulnerability can affect resources beyond the initially vulnerable component. The impact includes low confidentiality, integrity, and availability impacts (C:L/I:L/A:L), meaning that an attacker could potentially steal sensitive information, manipulate content, or disrupt availability to a limited extent. No known exploits are currently reported in the wild, and no patches are linked yet. The vulnerability was published on July 4, 2025, and reserved earlier in January 2025. The medium severity rating and CVSS score of 6.5 reflect a moderate risk, primarily due to the ease of exploitation and the potential for user-targeted attacks such as phishing or session hijacking via injected scripts.

For European organizations, this DOM-Based XSS vulnerability poses a moderate risk, especially for those utilizing the affected '(Simply) Guest Author Name' product in their web infrastructure. Successful exploitation could lead to unauthorized disclosure of sensitive user data, session token theft, or manipulation of web content, potentially damaging user trust and violating data protection regulations such as GDPR. The requirement for user interaction means phishing or social engineering campaigns could be used to trigger the exploit, increasing the risk to end-users and employees. Additionally, the scope change implies that the impact could extend beyond the immediate application, possibly affecting integrated services or third-party components. Organizations in sectors with high web presence, such as e-commerce, publishing, or online services, may face reputational damage and regulatory scrutiny if exploited. The lack of available patches necessitates proactive mitigation to prevent exploitation.

European organizations should implement the following specific mitigations: 1) Conduct a thorough audit of all instances of '(Simply) Guest Author Name' to identify affected versions and isolate vulnerable deployments. 2) Employ Content Security Policy (CSP) headers with strict script-src directives to limit the execution of unauthorized scripts and reduce the impact of DOM-based XSS. 3) Implement rigorous input validation and output encoding on the client side, especially for any dynamic DOM manipulations involving user input. 4) Educate users and employees about phishing risks and suspicious links that could trigger the exploit. 5) Monitor web application logs and client-side error reports for unusual script execution patterns indicative of exploitation attempts. 6) Engage with the vendor or community to obtain patches or updates as soon as they become available and plan for timely deployment. 7) Consider deploying web application firewalls (WAFs) with rules tailored to detect and block DOM-based XSS payloads targeting this product. 8) Review and limit privileges of users interacting with the vulnerable system to minimize exploitation potential.