CVE-2026-24392 identifies a stored Cross-site Scripting (XSS) vulnerability in HurryTimer, a web-based timer plugin developed by Nabil Lemsieh, affecting all versions up to and including 2.14.2. The vulnerability stems from improper neutralization of user-supplied input during web page generation, allowing malicious scripts to be injected and stored persistently within the application. When other users access the affected pages, the malicious payload executes in their browsers under the context of the HurryTimer domain. This can lead to theft of session cookies, user credentials, or execution of unauthorized actions, compromising user accounts and potentially the broader application environment. The vulnerability does not require authentication or complex user interaction beyond visiting a compromised page, increasing its exploitation potential. Although no public exploits have been reported yet, the nature of stored XSS makes it a critical concern for web applications that handle sensitive user data or administrative functions. HurryTimer is commonly used in various web environments, including European organizations that rely on it for time management or scheduling functionalities. The lack of an official patch or CVSS score at the time of publication necessitates proactive mitigation and monitoring. The vulnerability highlights the importance of proper input validation, output encoding, and secure coding practices in web application development to prevent injection flaws.

For European organizations, exploitation of this stored XSS vulnerability could lead to significant confidentiality breaches through session hijacking and credential theft. Integrity of user data and application workflows may be compromised if attackers execute unauthorized actions on behalf of legitimate users. Availability impacts are generally limited but could occur if attackers use the vulnerability to inject disruptive scripts or conduct phishing campaigns. Organizations with public-facing HurryTimer instances are particularly vulnerable, as attackers can easily lure users to maliciously crafted pages. The reputational damage and potential regulatory consequences under GDPR for failing to protect user data could be severe. Additionally, sectors such as finance, healthcare, and government that rely on HurryTimer for scheduling or time tracking may face operational disruptions. The absence of known exploits currently provides a window for remediation, but the ease of exploitation and stored nature of the XSS make it a persistent threat if left unaddressed.

European organizations should immediately audit their HurryTimer installations to identify affected versions (<= 2.14.2). Until an official patch is released, implement strict input validation on all user-supplied data fields, ensuring that scripts and HTML tags are sanitized or rejected. Employ robust output encoding techniques, such as context-aware escaping, to neutralize any injected content before rendering in the browser. Utilize Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS payloads. Regularly monitor web application logs and user reports for suspicious activities indicative of exploitation attempts. Educate users about the risks of clicking unknown links and encourage the use of updated browsers with built-in XSS protections. Once a vendor patch becomes available, prioritize its deployment across all affected systems. Additionally, consider implementing web application firewalls (WAFs) with rules tailored to detect and block XSS attack patterns specific to HurryTimer.