Vulnerability Details CVE-2025-12642
lighttpd1.4.80 incorrectly merged trailer fields into headers after 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
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 19.9%
CVSS Severity
CVSS v3 Score 9.1