CVE-2025-66119 is a reflected Cross-site Scripting (XSS) vulnerability identified in the Bob Hostel product, a software solution used for hostel management. The vulnerability stems from improper neutralization of input during web page generation, meaning that user-supplied data is not correctly sanitized or encoded before being included in the HTML output. This flaw allows an attacker to craft malicious URLs or inputs that, when processed by the vulnerable application, cause the victim's browser to execute arbitrary JavaScript code. The affected versions include all releases up to and including 1.1.5.9. Reflected XSS vulnerabilities typically require the victim to click a malicious link or visit a crafted page, which then reflects the attacker's payload back in the HTTP response. Exploitation can lead to session hijacking, theft of cookies or credentials, defacement, or redirection to malicious sites. Although no public exploits are currently known, the vulnerability is publicly disclosed and thus may be targeted by attackers. The absence of a CVSS score necessitates an evaluation based on the nature of the vulnerability: it affects confidentiality and integrity, is relatively easy to exploit without authentication, and impacts web-facing systems. The vulnerability is particularly concerning for organizations that rely on Bob Hostel software to manage bookings, user data, and other sensitive information. Without proper input validation and output encoding, attackers can leverage this flaw to compromise user sessions or perform unauthorized actions.

For European organizations, the impact of CVE-2025-66119 can be significant, especially for those in the hospitality and accommodation sectors using Bob Hostel software. Successful exploitation could lead to unauthorized access to user accounts, leakage of sensitive personal data, and potential reputational damage. Attackers might hijack sessions to impersonate legitimate users, manipulate bookings or payments, or distribute malware via injected scripts. This could also result in regulatory non-compliance under GDPR due to data breaches. The reflected XSS nature means that attacks require user interaction, but phishing campaigns could be used to lure victims. The overall availability of the service is less likely to be directly impacted, but indirect effects such as loss of customer trust and operational disruption are possible. Given the hospitality industry's importance in Europe, particularly in countries with large tourism sectors, the threat could affect a broad range of organizations from small hostels to larger chains.

To mitigate CVE-2025-66119, organizations should first verify if they are running affected versions of Bob Hostel (up to 1.1.5.9) and apply any available patches or updates from the vendor once released. In the absence of patches, implement strict input validation on all user-supplied data, ensuring that inputs conform to expected formats and reject suspicious characters. Employ context-aware output encoding (e.g., HTML entity encoding) before rendering user input in web pages to prevent script execution. Deploy Web Application Firewalls (WAFs) with rules designed to detect and block reflected XSS payloads. Educate users and staff about phishing risks to reduce the likelihood of successful exploitation via malicious links. Additionally, review and harden Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts. Regular security testing, including automated scanning and manual penetration testing focused on XSS, should be conducted to identify and remediate similar vulnerabilities. Logging and monitoring for unusual web requests can help detect exploitation attempts early.