CVE-2025-14523

Name of the Vulnerable Software and Affected Versions libsoup versions 2.4 and 3.x Description A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request, with the server processing the last occurrence. This discrepancy between how front proxies and the backend server handle the Host: header can lead to virtual host confusion. This can enable request-smuggling style attacks, cache poisoning, or bypassing host-based access controls when an attacker provides duplicate Host: headers. The vulnerability arises from a host-parsing discrepancy where the first value is honored by proxies, while the backend uses the last value. Recommendations Update libsoup to a newer version that addresses this issue.