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

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact Low

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00059.

Exploitation none

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
lighttpd lighttpd unaffected
Version Status Constraints
1.4.80 affected < 1.4.81

Configuration 1 [-]

cpe:2.3:a:lighttpd:lighttpd:1.4.80:*:*:*:*:*:*:*

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Lighttpd Subscribe
Lighttpd Subscribe

Project Subscriptions

Vendors Products
Lighttpd Subscribe
Lighttpd Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/lighttpd/lighttpd1.4/commit/35cb89c103877de62d6b63d0804255475d77e5e1 cve-icon cve-icon
History

Wed, 12 Nov 2025 14:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:lighttpd:lighttpd:1.4.80:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

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'}

Projects

Sign in to view the affected projects.

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 : Analyzed

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

Modified: 2025-11-12T14:34:27.037

Link: CVE-2025-12642

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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

Weaknesses