Undertow-core: undertow http server fails to reject malformed host headers leading to potential cache poisoning and ssrf
48Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 9.6epss 1.4%
from disclosure to weapon84 days
Published on NVDJan 7
1st PoC+84d
exploitation probability
1.4%top 30% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
Affected products
Red Hat · Red Hat build of Apache Camel 4.14.4 for Spring Boot 3.5.11Red Hat · 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 9Red Hat · Red Hat Fuse 7Red Hat · Red Hat JBoss Enterprise Application Platform 7Red Hat · Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7Red Hat · Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7Red Hat · Red Hat JBoss Enterprise Application Platform 7.4.24Red Hat · Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7Red Hat · Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8Red Hat · Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9Red Hat · Red Hat JBoss Enterprise Application Platform 8.0Red Hat · Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8Red Hat · Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 9Red Hat · Red Hat JBoss Enterprise Application Platform 8.1.6Red Hat · Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Red Hat · Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Red Hat · Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat · Red Hat Process Automation 7Red Hat · Red Hat Single Sign-On 7public PoCs found — 1
githubgithub.com/kavin71725/CVE-2025-12543-Fix-for-Wildfly★ 0⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
References
https://access.redhat.com/errata/RHSA-2026:0383https://access.redhat.com/errata/RHSA-2026:0384https://access.redhat.com/errata/RHSA-2026:0386https://access.redhat.com/errata/RHSA-2026:33371https://access.redhat.com/errata/RHSA-2026:33372https://access.redhat.com/errata/RHSA-2026:3889https://access.redhat.com/errata/RHSA-2026:3890https://access.redhat.com/errata/RHSA-2026:3891https://access.redhat.com/errata/RHSA-2026:3892https://access.redhat.com/errata/RHSA-2026:4915https://access.redhat.com/errata/RHSA-2026:4916https://access.redhat.com/errata/RHSA-2026:4917