CVE-2025-12543
CRITICAL
9.6
Our Analysis: General-Purpose
Our model has classified this vulnerability as relevant to General-Purpose Systems, helping your team prioritize efforts effectively.
Published Date
January 7, 2026
Last Modified
January 8, 2026
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
Description
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.