CVE-2026-3763 identifies a cross-site scripting (XSS) vulnerability in the Simple Flight Ticket Booking System version 1.0 developed by code-projects. The vulnerability resides in an unspecified function within the showhistory.php file, which improperly handles user-supplied input, allowing attackers to inject malicious JavaScript code. This flaw can be exploited remotely without authentication, but requires user interaction to execute the malicious payload, such as clicking a crafted link or viewing manipulated content. The vulnerability is categorized as reflected or stored XSS, enabling attackers to steal session cookies, perform phishing attacks, or manipulate the user interface to deceive users. The CVSS v4.0 base score is 5.3 (medium severity), reflecting the network attack vector, low attack complexity, no privileges required, but requiring user interaction and resulting in limited integrity impact. No vendor patches or mitigations have been published yet, and while no active exploitation has been observed, the public availability of exploit code increases the risk of future attacks. The vulnerability affects only version 1.0 of the product, which is a niche flight booking system, limiting the scope but still posing risks to organizations relying on this software for ticket management and customer interactions.

The primary impact of CVE-2026-3763 is on the confidentiality and integrity of user data within the affected flight booking system. Successful exploitation can lead to session hijacking, enabling attackers to impersonate legitimate users and potentially access sensitive booking information or personal data. Phishing attacks facilitated by injected scripts can compromise user credentials or lead to further malware infections. Although the vulnerability does not directly affect system availability, the resulting loss of user trust and potential regulatory consequences from data breaches can have significant operational and reputational impacts. Organizations using this system may face customer dissatisfaction, legal liabilities, and increased security costs. The limited scope to version 1.0 and the absence of known active exploitation reduce immediate widespread risk, but the public exploit availability necessitates prompt mitigation to prevent targeted attacks.

To mitigate CVE-2026-3763, organizations should implement strict input validation and output encoding on all user-supplied data processed by showhistory.php and related components. Employing a web application firewall (WAF) with rules to detect and block common XSS payloads can provide an additional layer of defense. Since no official patches are available, consider isolating or restricting access to the vulnerable application, especially from untrusted networks. Conduct thorough code reviews to identify and sanitize all input vectors, and adopt Content Security Policy (CSP) headers to limit the execution of unauthorized scripts. Educate users about the risks of clicking suspicious links and monitor logs for unusual activity indicative of exploitation attempts. Planning an upgrade or migration to a more secure booking system version or alternative product is advisable once patches or updates become available. Regular security assessments and penetration testing should be performed to verify the effectiveness of these mitigations.