CVE-2025-12543

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

Published Jan 7, 2026 CVSS 3.1 · 9.6 Critical EPSS 1.3% KEV · Not listed
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.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use, applicability, or stability.

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-j382-5jj3-vw4j Undertow HTTP server core doesn't properly validate the Host header in incoming HTTP requests
Ubuntu USN Ubuntu USN USN-8144-1 Undertow vulnerability
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat jboss Bpms
CPEs cpe:/a:redhat:jboss_enterprise_bpms_platform:7
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:jboss_bpms:7
cpe:/a:redhat:jboss_enterprise_application_platform:8.1
Vendors & Products Redhat jboss Enterprise Bpms Platform
Redhat jboss Bpms
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
CPEs cpe:/a:redhat:red_hat_single_sign_on:7.6::el7
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:red_hat_single_sign_on:7.6::el8
cpe:/a:redhat:red_hat_single_sign_on:7.6::el9
References
Type Values Removed Values Added
First Time appeared Redhat rhosemc
CPEs cpe:/a:redhat:red_hat_single_sign_on:7 cpe:/a:redhat:red_hat_single_sign_on:7.6
cpe:/a:redhat:rhosemc:1.0::el8
Vendors & Products Redhat rhosemc
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:7
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:7
Type Values Removed Values Added
First Time appeared Redhat jboss Enterprise Application Platform Eus
CPEs cpe:/a:redhat:jboss_enterprise_application_platform_eus:7.1::el7
cpe:/a:redhat:jboss_enterprise_application_platform_eus:7.3::el7
Vendors & Products Redhat jboss Enterprise Application Platform Eus
References
Type Values Removed Values Added
CPEs cpe:/o:redhat:rhivos:1
Vendors & Products Redhat rhivos
Type Values Removed Values Added
First Time appeared Redhat rhivos
CPEs cpe:/o:redhat:rhivos:1
Vendors & Products Redhat rhivos
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:7
Type Values Removed Values Added
First Time appeared Redhat jboss Enterprise Application Platform Els
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:7 cpe:/a:redhat:jboss_enterprise_application_platform:7.4
cpe:/a:redhat:jboss_enterprise_application_platform_els:7.4::el7
cpe:/a:redhat:jboss_enterprise_application_platform_els:7.4::el8
cpe:/a:redhat:jboss_enterprise_application_platform_els:7.4::el9
Vendors & Products Redhat jboss Enterprise Application Platform Els
References
Type Values Removed Values Added
First Time appeared Redhat build Of Apache Camel
Redhat data Grid
Redhat fuse
Redhat jboss Enterprise Application Platform Expansion Pack
Redhat process Automation
Redhat single Sign-on
Redhat undertow
CPEs cpe:2.3:a:redhat:build_of_apache_camel:*:*:*:*:*:spring_boot:*:*
cpe:2.3:a:redhat:data_grid:8.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:fuse:7.0.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_enterprise_application_platform:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_enterprise_application_platform:-:*:*:*:text-only:*:*:*
cpe:2.3:a:redhat:jboss_enterprise_application_platform:7.0.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_enterprise_application_platform_expansion_pack:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:process_automation:7.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:single_sign-on:7.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:undertow:*:*:*:*:*:*:*:*
Vendors & Products Redhat build Of Apache Camel
Redhat data Grid
Redhat fuse
Redhat jboss Enterprise Application Platform Expansion Pack
Redhat process Automation
Redhat single Sign-on
Redhat undertow
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat apache Camel Spring Boot
CPEs cpe:/a:redhat:camel_spring_boot:4 cpe:/a:redhat:apache_camel_spring_boot:4.14
Vendors & Products Redhat camel Spring Boot
Redhat apache Camel Spring Boot
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el8
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:8 cpe:/a:redhat:jboss_enterprise_application_platform:8.0::el8
cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Undertow-core: undertow http server fails to reject malformed host headers leading to potential cache poisoning and ssrf
First Time appeared Redhat
Redhat apache Camel Hawtio
Redhat camel Spring Boot
Redhat enterprise Linux
Redhat jboss Data Grid
Redhat jboss Enterprise Application Platform
Redhat jboss Enterprise Bpms Platform
Redhat jboss Fuse
Redhat jbosseapxp
Redhat red Hat Single Sign On
Weaknesses CWE-20
CPEs cpe:/a:redhat:apache_camel_hawtio:4
cpe:/a:redhat:camel_spring_boot:4
cpe:/a:redhat:jboss_data_grid:8
cpe:/a:redhat:jboss_enterprise_application_platform:7
cpe:/a:redhat:jboss_enterprise_application_platform:8
cpe:/a:redhat:jboss_enterprise_bpms_platform:7
cpe:/a:redhat:jboss_fuse:7
cpe:/a:redhat:jbosseapxp
cpe:/a:redhat:red_hat_single_sign_on:7
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat apache Camel Hawtio
Redhat camel Spring Boot
Redhat enterprise Linux
Redhat jboss Data Grid
Redhat jboss Enterprise Application Platform
Redhat jboss Enterprise Bpms Platform
Redhat jboss Fuse
Redhat jbosseapxp
Redhat red Hat Single Sign On
References
Metrics cvssV3_1

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