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
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 04 Nov 2025 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Lighttpd
Lighttpd lighttpd
Vendors & Products Lighttpd
Lighttpd lighttpd

Mon, 03 Nov 2025 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 03 Nov 2025 19:45:00 +0000

Type Values Removed Values Added
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
Title HTTP Header Smuggling via Trailer Merge
Weaknesses CWE-444
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Toreon

Published:

Updated: 2025-11-03T19:44:09.174Z

Reserved: 2025-11-03T19:34:17.666Z

Link: CVE-2025-12642

cve-icon Vulnrichment

Updated: 2025-11-03T19:43:58.912Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-11-03T20:17:06.410

Modified: 2025-11-04T15:41:31.450

Link: CVE-2025-12642

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-11-04T16:34:48Z