Home/CVE/A flaw was found in the Undertow HTTP server core, which is used in WildFly, JBoss EAP, and other Java applications. The
CVE

CVE-2025-12543

A flaw was found in the Undertow HTTP server core, which is used in WildFly, JBoss EAP, and other Java applications. The

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.

CRITICAL · CVSS 9.6 EPSS 0.0005
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-20Improper Input Validation
▤

Affected Products & Versions

11
redhat build of apache camel< 4.14.4
redhat data gridall versions
redhat fuseall versions
redhat jboss enterprise application platform>= 8.0 and < 8.0.12
redhat jboss enterprise application platform>= 8.1.0 and < 8.1.3
redhat jboss enterprise application platformall versions
redhat jboss enterprise application platform expansion packall versions
redhat process automationall versions
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Maven io.undertow:undertow-core CRITICAL
▣

Scoring & Timeline

9.6
CRITICAL · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD07 Jan 2026 · 05:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

13
usnUSN-8144-1
rhsaRHSA-2026:3890Important
rhsaRHSA-2026:4924Important
rhsaRHSA-2026:4915Important
rhsaRHSA-2026:4916Important
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://access.redhat.com/security/cve/CVE-2025-12543Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2408784Issue TrackingVendor Advisory
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin