CVE-2026-24469 is a path traversal vulnerability identified in frustratedProton's http-server, an HTTP/1.1 server designed to handle client connections and serve HTTP requests. Versions 1.0 and earlier are affected. The vulnerability exists in the RequestHandler::handleRequest method, where the server processes the URL path from incoming HTTP GET requests. The server fails to properly sanitize the filename variable derived from the user-controlled URL path, directly concatenating it to the base files_directory path. This improper limitation of pathname (CWE-22) allows attackers to craft malicious requests containing '../' sequences to traverse directories outside the intended root directory. As a result, an unauthenticated remote attacker can read arbitrary files on the server's filesystem, potentially exposing sensitive configuration files, credentials, or other confidential data. The vulnerability has a CVSS 3.1 base score of 7.5, reflecting high severity due to its ease of exploitation (network attack vector, no privileges or user interaction required) and high impact on confidentiality. No patches or fixes were available at the time of disclosure, and no known exploits have been observed in the wild. The flaw does not affect integrity or availability, but the confidentiality breach can lead to further attacks or data leaks. The server's usage in various environments, especially those hosting sensitive data or critical services, increases the risk posed by this vulnerability.

For European organizations, this vulnerability poses a significant risk to data confidentiality. Attackers exploiting this flaw can access sensitive files such as configuration files, credentials, or proprietary information stored on the server. This exposure can lead to further compromise, including lateral movement within networks or targeted attacks on critical infrastructure. Organizations in sectors like finance, healthcare, government, and critical infrastructure are particularly vulnerable due to the sensitivity of their data. The lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the likelihood of exploitation. Additionally, the absence of a patch means organizations must rely on mitigations or workarounds, potentially leaving systems exposed for extended periods. The vulnerability could also undermine compliance with European data protection regulations such as GDPR if personal or sensitive data is exposed. Overall, the threat could result in reputational damage, regulatory penalties, and operational disruptions if exploited.

1. Implement strict input validation and sanitization on the server side to reject or properly normalize any URL paths containing '../' or other traversal sequences before processing. 2. Employ a whitelist approach for allowed file paths or extensions to restrict accessible resources. 3. Deploy Web Application Firewalls (WAFs) configured to detect and block path traversal attack patterns in HTTP requests. 4. Run the http-server with the least privileges necessary and isolate it within a sandbox or container environment to limit filesystem exposure. 5. Monitor server logs for suspicious requests containing traversal sequences or unusual file access patterns. 6. If possible, disable or restrict access to sensitive directories and files on the server filesystem. 7. Engage with the vendor or community to obtain patches or updates as they become available and plan for timely deployment. 8. Conduct regular security assessments and penetration testing to identify and remediate similar vulnerabilities proactively.