Lighttpd Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling) Vulnerability - CVE-2025-12642

lighttpd1.4.80 incorrectly merged trailer fields into headersafter http request parsing. This behavior can be exploited to conduct HTTP Header Smuggling attacks. Successful exploitation may allow an attacker to: Bypass access control rules Inject unsafe input into backend logic that trusts request headers Execute HTTP Request Smuggling attacks under some conditions This issue affects lighttpd1.4.80