What is the CVSS score of CVE-2025-12543?

CVE-2025-12543 has a CVSS 3.1 base score of 9.6 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Java are affected by CVE-2025-12543?

Organizations using A flaw face critical risk from CVE-2025-12543, a input validation vulnerability rated CVSS 9.6.. A patch is available.

How to fix or mitigate CVE-2025-12543?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Monitor vendor channels for patch availability.

Java CVE-2025-12543

CRITICAL

Improper Input Validation (CWE-20)

2026-01-07 secalert@redhat.com

GHSA-j382-5jj3-vw4j

Java Information Disclosure Process Automation Jboss Enterprise Application Platform Expansion Pack Jboss Enterprise Application Platform Undertow Build Of Apache Camel Fuse Data Grid Single Sign On

9.6

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.6 CRITICAL

AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Red Hat

9.6 HIGH

qualitative

Primary rating from NVD.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

CVE Published

Jan 07, 2026 - 17:15 nvd

CRITICAL 9.6

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

45 maven packages depend on io.undertow:undertow-core (9 direct, 36 indirect)

Ecosystem-wide dependent count for version 2.3.0.Alpha1.

DescriptionNVD

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.

AnalysisAI

Undertow HTTP server (used in WildFly, JBoss EAP) fails to validate Host headers, enabling cache poisoning, internal network scanning, and session hijacking. Affects a widely-used Java application server component.

Technical ContextAI

Undertow does not reject requests with malformed or malicious Host headers (CWE-20). This enables: (1) Cache poisoning by injecting different Host values that get cached, (2) Internal network scanning by using Host headers to probe internal services, (3) Session hijacking through Host header-based routing manipulation.