CVE-2026-1406 identifies an open redirect vulnerability in the BootDo web application framework developed by lcg0124. The vulnerability resides in the redirectToLogin function within AccessControlFilter.java, part of the Host Header Handler component. Specifically, the function improperly handles the Hostname argument, allowing an attacker to manipulate it to redirect users to arbitrary external URLs. This flaw can be exploited remotely without authentication, though it requires user interaction to follow the malicious redirect link. Open redirect vulnerabilities are commonly abused in phishing campaigns to trick users into visiting malicious sites under the guise of a trusted domain. The BootDo product follows a rolling release model, which means updates are continuously delivered without fixed version numbers, making it difficult to pinpoint exact affected versions or patch releases. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P) indicates network attack vector, low attack complexity, no privileges required, user interaction needed, no impact on confidentiality or availability, and low impact on integrity. No public exploits are currently known, but the vulnerability has been publicly disclosed, increasing the risk of future exploitation. The vulnerability primarily facilitates social engineering attacks rather than direct system compromise. Organizations using BootDo in their web infrastructure should assess their exposure and apply mitigations promptly.

For European organizations, this vulnerability poses a moderate risk primarily through social engineering and phishing attacks. Attackers can craft URLs that appear to originate from legitimate BootDo-hosted sites but redirect users to malicious domains, potentially leading to credential theft, malware infection, or further exploitation. While the vulnerability does not directly compromise system confidentiality, integrity, or availability, it undermines user trust and can serve as a vector for broader attacks. Sectors with high reliance on web applications for customer interaction, such as finance, government, and e-commerce, are particularly at risk. The rolling release model of BootDo complicates patch management, potentially delaying remediation. Additionally, organizations with less mature security awareness programs may be more susceptible to successful phishing campaigns leveraging this flaw. The medium CVSS score reflects the limited direct technical impact but acknowledges the significant indirect risks through user deception.

To mitigate CVE-2026-1406, organizations should implement strict validation and sanitization of all redirect URLs within BootDo applications, ensuring only trusted, internal destinations are allowed. Employ an allowlist approach for redirect targets rather than blacklists to prevent bypass. Modify the redirectToLogin function to reject or neutralize any Hostname parameters that do not match expected internal domains. Deploy web application firewalls (WAFs) with rules to detect and block suspicious redirect patterns. Educate users and staff about the risks of clicking on unexpected or suspicious links, emphasizing verification of URLs before interaction. Monitor logs for unusual redirect activity that could indicate exploitation attempts. Engage with the BootDo vendor or community to obtain security updates or patches as they become available, despite the rolling release model. Consider implementing Content Security Policy (CSP) headers to restrict navigation to trusted domains. Finally, conduct regular security assessments and penetration tests focusing on open redirect and related web vulnerabilities.