CVE-2025-12543 PUBLISHED

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

Assigner: redhat
Reserved: 31.10.2025 Published: 07.01.2026 Updated: 09.01.2026

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.

Metrics

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

Product Status

Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1
Versions Default: unaffected
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:4.0.10-1.redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:1.82.0-1.redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:801.3.0-1.GA_redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:1.0.1-3.redhat_00003.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:6.6.36-1.Final_redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:4.0.2-1.Final_redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:2.5.0-1.redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:2.3.20-2.SP4_redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:8.1.3-4.GA_redhat_00006.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:5.0.12-1.Final_redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:2.6.6-1.Final_redhat_00001.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
Versions Default: affected
  • unaffected from 0:8.1.1-4.GA_redhat_00007.1.el8eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:4.0.10-1.redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:1.82.0-1.redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:801.3.0-1.GA_redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:1.0.1-3.redhat_00003.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:6.6.36-1.Final_redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:4.0.2-1.Final_redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:2.5.0-1.redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:2.3.20-2.SP4_redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:8.1.3-4.GA_redhat_00006.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:5.0.12-1.Final_redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:2.6.6-1.Final_redhat_00001.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Versions Default: affected
  • unaffected from 0:8.1.1-4.GA_redhat_00007.1.el9eap to * (excl.)
Vendor Red Hat
Product Red Hat build of Apache Camel for Spring Boot 4
Versions Default: affected
Vendor Red Hat
Product Red Hat build of Apache Camel - HawtIO 4
Versions Default: unaffected
Vendor Red Hat
Product Red Hat Data Grid 8
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 10
Versions Default: unaffected
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: unaffected
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: unaffected
Vendor Red Hat
Product Red Hat Enterprise Linux 9
Versions Default: affected
Vendor Red Hat
Product Red Hat Fuse 7
Versions Default: affected
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform 7
Versions Default: affected
Vendor Red Hat
Product Red Hat JBoss Enterprise Application Platform Expansion Pack
Versions Default: affected
Vendor Red Hat
Product Red Hat Process Automation 7
Versions Default: affected
Vendor Red Hat
Product Red Hat Single Sign-On 7
Versions Default: affected

Workarounds

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.

Credits

  • Red Hat would like to thank Ahmet Artuç for reporting this issue.

References

Problem Types

  • Improper Input Validation CWE