CVE-2025-52749 identifies a reflected Cross-site Scripting (XSS) vulnerability in the Activity Track Uji Countdown application, specifically versions up to and including 2.3.3. The root cause is improper neutralization of user-supplied input during the dynamic generation of web pages, which allows malicious scripts to be injected and executed in the context of a victim's browser session. Reflected XSS typically occurs when input from HTTP requests is immediately included in the response without sufficient sanitization or encoding. This vulnerability enables attackers to craft malicious URLs or payloads that, when visited by users, execute arbitrary JavaScript code. The CVSS vector indicates that the attack can be launched remotely over the network (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability can affect resources beyond the vulnerable component. The impact includes partial loss of confidentiality, integrity, and availability (C:L/I:L/A:L), such as session token theft, defacement, or redirection to malicious sites. Although no known exploits are currently reported in the wild and no patches have been released, the vulnerability poses a significant risk due to the ease of exploitation and potential impact. The vulnerability affects organizations using Uji Countdown for activity or event tracking, which may be integrated into broader enterprise systems or customer-facing portals. Attackers could leverage this vulnerability for phishing, credential theft, or spreading malware. The lack of patches necessitates immediate mitigation efforts to reduce exposure. The vulnerability was reserved in June 2025 and published in October 2025, indicating recent discovery and disclosure.

For European organizations, the reflected XSS vulnerability in Uji Countdown could lead to significant security incidents including session hijacking, unauthorized access to sensitive information, and manipulation of web content presented to users. This can damage organizational reputation, lead to data breaches, and facilitate further attacks such as phishing or malware distribution. Sectors relying on Uji Countdown for scheduling, event management, or activity tracking—such as education, public administration, and event management companies—are particularly at risk. The vulnerability’s ability to affect confidentiality, integrity, and availability means that both internal users and external customers could be targeted, potentially disrupting business operations and eroding trust. Additionally, the cross-site scripting flaw could be chained with other vulnerabilities to escalate attacks. Given the interconnected nature of European IT infrastructures, exploitation in one organization could have cascading effects. The absence of patches increases the window of exposure, making proactive mitigation critical. Organizations with high web traffic and user interaction are more vulnerable to exploitation attempts.

European organizations should implement multiple layers of defense to mitigate this reflected XSS vulnerability. First, apply strict input validation on all user-supplied data, ensuring that only expected characters and formats are accepted. Second, implement proper output encoding (e.g., HTML entity encoding) before reflecting any user input in web pages to neutralize malicious scripts. Third, deploy a robust Content Security Policy (CSP) to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Fourth, conduct thorough code reviews and security testing focusing on input handling and output generation in Uji Countdown integrations. Fifth, educate users and administrators about the risks of clicking on suspicious links and encourage reporting of unusual behavior. Sixth, monitor web traffic and logs for signs of attempted XSS exploitation, such as unusual URL parameters or script injection patterns. Seventh, isolate the Uji Countdown application within network segments to limit lateral movement if compromised. Finally, maintain communication with the vendor or community for updates and patches, and plan for rapid deployment once available. If possible, consider temporary disabling or restricting access to vulnerable features until a fix is released.