CVE-2025-12642

Name	CVE-2025-12642
Description	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
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
lighttpd (PTS)	bookworm	1.4.69-1	fixed
	trixie	1.4.79-2	fixed
	forky, sid	1.4.85-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
lighttpd	source	(unstable)	(not affected)

Notes

- lighttpd <not-affected> (Vulnerable code not present)
Introduced with: https://github.com/lighttpd/lighttpd1.4/commit/90002f4fd8db552b8ebe260e06c890a7f7d7e468 (lighttpd-1.4.80)
Fixed by: https://github.com/lighttpd/lighttpd1.4/commit/35cb89c103877de62d6b63d0804255475d77e5e1 (lighttpd-1.4.81)