CVE-2025-12543

Undertow-core: undertow http server fails to reject malformed host headers leading to potential cache poisoning and ssrf

State: Published
Severity: 9.6 Critical
Published: Jan 7, 2026
Updated: Oct 14, 2026
Reserved: Oct 31, 2025

Read the record on cve.org

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.

Scores

CVSS	Score	Vector	Source
3.1	9.6 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L	redhat
3.1	9.6 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L	redhat-SADP

Weaknesses

CWE-20 Improper Input Validation

Affected Products

Product	Versions
Red Hat build of Apache Camel 4.14.4 for Spring Boot 3.5.11Red Hat
Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7Red Hat	0:1.4.18-21.SP19_redhat_00001.1.ep7.el7 and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7Red Hat	0:2.0.41-8.SP9_redhat_00001.1.el7eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.4.24Red Hat	2.2.39.Final-redhat-00001 and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7Red Hat	0:2.2.39-1.Final_redhat_00001.1.el7eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7Red Hat	0:7.4.24-4.GA_redhat_00002.1.el7eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8Red Hat	0:2.2.39-1.Final_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8Red Hat	0:7.4.24-4.GA_redhat_00002.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9Red Hat	0:2.2.39-1.Final_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9Red Hat	0:7.4.24-4.GA_redhat_00002.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0Red Hat
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8Red Hat	0:1.83.0-1.redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8Red Hat	0:33.0.0-2.jre_redhat_00003.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8Red Hat	0:4.0.6-1.redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8Red Hat	0:1.0.0-3.redhat_00009.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8Red Hat	0:2.0.2-1.Final_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8Red Hat	0:2.3.23-1.SP3_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 9Red Hat	0:1.83.0-1.redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 9Red Hat	0:33.0.0-2.jre_redhat_00003.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 9Red Hat	0:4.0.6-1.redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 9Red Hat	0:1.0.0-3.redhat_00009.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 9Red Hat	0:2.0.2-1.Final_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 9Red Hat	0:2.3.23-1.SP3_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1.3Red Hat	2.3.20.SP4-redhat-00001 and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:4.0.10-1.redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:1.82.0-1.redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:801.3.0-1.GA_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:1.0.1-3.redhat_00003.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:6.6.36-1.Final_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:4.0.2-1.Final_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:2.5.0-1.redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:2.3.20-2.SP4_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:8.1.3-4.GA_redhat_00006.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:5.0.12-1.Final_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:2.6.6-1.Final_redhat_00001.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat	0:8.1.1-4.GA_redhat_00007.1.el8eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:4.0.10-1.redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:1.82.0-1.redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:801.3.0-1.GA_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:1.0.1-3.redhat_00003.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:6.6.36-1.Final_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:4.0.2-1.Final_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:2.5.0-1.redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:2.3.20-2.SP4_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:8.1.3-4.GA_redhat_00006.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:5.0.12-1.Final_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:2.6.6-1.Final_redhat_00001.1.el9eap and laterNot affected
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat	0:8.1.1-4.GA_redhat_00007.1.el9eap and laterNot affected
Red Hat Single Sign-On 7.6.13Red Hat
Red Hat Single Sign-On 7.6 for RHEL 7Red Hat	0:18.0.20-1.redhat_00001.1.el7sso and laterNot affected
Red Hat Single Sign-On 7.6 for RHEL 8Red Hat	0:18.0.20-1.redhat_00001.1.el8sso and laterNot affected
Red Hat Single Sign-On 7.6 for RHEL 9Red Hat	0:18.0.20-1.redhat_00001.1.el9sso and laterNot affected
RHEL-8 based Middleware ContainersRed Hat	7.6-85 and laterNot affected
Red Hat build of Apache Camel - HawtIO 4Red Hat
Red Hat Data Grid 8Red Hat
Red Hat Enterprise Linux 10Red Hat
Red Hat Enterprise Linux 8Red Hat
Red Hat Enterprise Linux 8Red Hat
Red Hat Enterprise Linux 9Red Hat
Red Hat Fuse 7Red Hat
Red Hat JBoss Enterprise Application Platform 7Red Hat
Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat
Red Hat Process Automation 7Red Hat

References

RHSA-2026:0383vendor-advisory
RHSA-2026:0384vendor-advisory
RHSA-2026:0386vendor-advisory
RHSA-2026:33371vendor-advisory
RHSA-2026:33372vendor-advisory
RHSA-2026:3889vendor-advisory
RHSA-2026:3890vendor-advisory
RHSA-2026:3891vendor-advisory
RHSA-2026:3892vendor-advisory
RHSA-2026:4915vendor-advisory
RHSA-2026:4916vendor-advisory
RHSA-2026:4917vendor-advisory
RHSA-2026:4924vendor-advisory
RHSA-2026:76128vendor-advisory
RHSA-2026:76129vendor-advisory
RHSA-2026:76130vendor-advisory
RHSA-2026:76132vendor-advisory
RHSA-2026:76134vendor-advisory
https://access.redhat.com/security/cve/CVE-2025-12543vdb-entry
RHBZ#2408784issue-tracking
https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-12543.json

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