CVE-2025-62146 is a stored Cross-site Scripting (XSS) vulnerability classified under CWE-79, found in the Maksym Marko MX Time Zone Clocks software, affecting all versions up to 5.1.1. The vulnerability occurs due to improper neutralization of user-supplied input during the generation of web pages, allowing malicious scripts to be stored and subsequently executed in the context of users accessing the affected pages. This stored XSS can be exploited by an attacker who has the ability to submit input to the application, which is then rendered without adequate sanitization or encoding. The CVSS 3.1 base score of 6.5 reflects a medium severity, with attack vector being network-based, low attack complexity, requiring privileges to submit input (PR:L), and user interaction (UI:R). The scope is changed (S:C), indicating that exploitation can affect components beyond the vulnerable component. The impact includes partial loss of confidentiality, integrity, and availability, as malicious scripts can steal session tokens, manipulate page content, or perform actions on behalf of users. No patches or fixes have been released yet, and no known exploits have been reported in the wild. The vulnerability is particularly concerning for deployments where multiple users access the MX Time Zone Clocks interface, as it can facilitate phishing, session hijacking, or further compromise of user accounts. The vulnerability was reserved in early October 2025 and published at the end of December 2025.

For European organizations, this vulnerability poses a risk primarily to web-facing installations of MX Time Zone Clocks, especially in environments where multiple users interact with the application, such as corporate intranets or public-facing dashboards. Exploitation could lead to unauthorized disclosure of sensitive information, session hijacking, and potential lateral movement within networks. The partial compromise of integrity and availability could disrupt time synchronization displays critical for operational processes. Given the medium severity and the need for some privileges and user interaction, the threat is moderate but should not be underestimated in sectors with high reliance on accurate time zone data, such as finance, transportation, and telecommunications. Additionally, stored XSS vulnerabilities can be leveraged as a foothold for more complex attacks, increasing the overall risk profile. The absence of known exploits currently provides a window for proactive mitigation, but the presence of this vulnerability in a widely used product could attract attackers once public awareness grows.

European organizations should implement the following specific mitigations: 1) Immediately audit all instances of MX Time Zone Clocks for exposure, especially those accessible via the internet or shared internally. 2) Restrict input privileges to trusted users only and implement strict input validation and sanitization at the application layer, even if vendor patches are pending. 3) Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts and reduce the impact of potential XSS payloads. 4) Monitor logs for unusual input patterns or suspicious activity related to the time zone clocks interface. 5) Educate users about the risks of interacting with unexpected or suspicious content within the application. 6) Where possible, isolate the MX Time Zone Clocks application within segmented network zones to limit lateral movement if compromised. 7) Engage with the vendor for timely patch releases and apply updates promptly once available. 8) Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block common XSS attack vectors targeting this product. These measures go beyond generic advice by focusing on access control, proactive monitoring, and layered defenses tailored to the specific vulnerability context.