CVE-2025-12543

Updated on 07 Jan 2026

Severity

9.6 Critical severity

Details

CVSS score
9.6
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L

Overview

About vulnerability

A flaw was found in the Undertow HTTP server core, which is used in WildFly, JBoss EAP, and other Java applications. The Undertow library fails to properly validate the Host header in incoming HTTP requests.As a result, requests containing malformed or malicious Host headers are processed without rejection, enabling attackers to poison caches, perform internal network scans, or hijack user sessions.

Details

Affected product:
Spring , Wildfly , cxf , undertow , wildfly
Affected packages:
cxf-tools-wsdlto-frontend-javascript @ 3.5.11 (+1304 more)
A flaw was found in the Undertow HTTP server core, which is used in WildFly, JBoss EAP, and other Java applications. The Undertow library fails to properly validate the Host header in incoming HTTP requests.As a result, requests containing malformed or malicious Host headers are processed without rejection, enabling attackers to poison caches, perform internal network scans, or hijack user sessions.

Fixes