cvelistv5 - cve-2025-12543

CVE-2025-12543 (GCVE-0-2025-12543)

Vulnerability from cvelistv5 – Published: 2026-01-07 16:04 – Updated: 2026-01-08 16:58

Title

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

Summary

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.

Severity ?

9.6 (Critical)


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

CWE

CWE-20 - Improper Input Validation

Assigner

redhat

References

URL

Tags

	https://access.redhat.com/errata/RHSA-2026:0384	vendor-advisoryx_refsource_REDHAT
	https://access.redhat.com/errata/RHSA-2026:0386	vendor-advisoryx_refsource_REDHAT
	https://access.redhat.com/security/cve/CVE-2025-12543	vdb-entryx_refsource_REDHAT
	https://bugzilla.redhat.com/show_bug.cgi?id=2408784	issue-trackingx_refsource_REDHAT

Impacted products

Vendor

Product

Version

Red Hat

Red Hat JBoss Enterprise Application Platform 8.1

cpe:/a:redhat:jboss_enterprise_application_platform:8.0::el8

Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:4.0.10-1.redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:1.82.0-1.redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:801.3.0-1.GA_redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:1.0.1-3.redhat_00003.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:6.6.36-1.Final_redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:4.0.2-1.Final_redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:2.5.0-1.redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:2.3.20-2.SP4_redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:8.1.3-4.GA_redhat_00006.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:5.0.12-1.Final_redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:2.6.6-1.Final_redhat_00001.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9	Unaffected: 0:8.1.1-4.GA_redhat_00007.1.el9eap , < * (rpm) cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
Red Hat	Red Hat build of Apache Camel for Spring Boot 4	cpe:/a:redhat:camel_spring_boot:4
Red Hat	Red Hat build of Apache Camel - HawtIO 4	cpe:/a:redhat:apache_camel_hawtio:4
Red Hat	Red Hat Data Grid 8	cpe:/a:redhat:jboss_data_grid:8
Red Hat	Red Hat Enterprise Linux 10	cpe:/o:redhat:enterprise_linux:10
Red Hat	Red Hat Enterprise Linux 8	cpe:/o:redhat:enterprise_linux:8
Red Hat	Red Hat Enterprise Linux 8	cpe:/o:redhat:enterprise_linux:8
Red Hat	Red Hat Enterprise Linux 9	cpe:/o:redhat:enterprise_linux:9
Red Hat	Red Hat Fuse 7	cpe:/a:redhat:jboss_fuse:7
Red Hat	Red Hat JBoss Enterprise Application Platform 7	cpe:/a:redhat:jboss_enterprise_application_platform:7
Red Hat	Red Hat JBoss Enterprise Application Platform Expansion Pack	cpe:/a:redhat:jbosseapxp
Red Hat	Red Hat Process Automation 7	cpe:/a:redhat:jboss_enterprise_bpms_platform:7
Red Hat	Red Hat Single Sign-On 7	cpe:/a:redhat:red_hat_single_sign_on:7

Credits

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

Show details on NVD website

JSON

To clipboard

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GHSA-J382-5JJ3-VW4J

Vulnerability from github – Published: 2026-01-07 18:30 – Updated: 2026-01-08 18:30

Summary

Undertow HTTP server core doesn't properly validate the Host header in incoming HTTP requests

Details

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.

Severity ?

9.6 (Critical)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.undertow:undertow-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2.4.0.Alpha1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-12543"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-01-08T17:15:55Z",
    "nvd_published_at": "2026-01-07T17:15:55Z",
    "severity": "CRITICAL"
  },
  "details": "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.",
  "id": "GHSA-j382-5jj3-vw4j",
  "modified": "2026-01-08T18:30:43Z",
  "published": "2026-01-07T18:30:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-12543"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:0384"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:0386"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2025-12543"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2408784"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/undertow-io/undertow"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Undertow HTTP server core doesn\u0027t properly validate the Host header in incoming HTTP requests"
}

FKIE_CVE-2025-12543

Vulnerability from fkie_nvd - Published: 2026-01-07 17:15 - Updated: 2026-01-08 18:08

Severity ?

9.6 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L

Summary

References

	URL	Tags
	secalert@redhat.com	https://access.redhat.com/errata/RHSA-2026:0384
	secalert@redhat.com	https://access.redhat.com/errata/RHSA-2026:0386
	secalert@redhat.com	https://access.redhat.com/security/cve/CVE-2025-12543
	secalert@redhat.com	https://bugzilla.redhat.com/show_bug.cgi?id=2408784

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2025-12543",
  "lastModified": "2026-01-08T18:08:54.147",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 9.6,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 6.0,
        "source": "secalert@redhat.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-01-07T17:15:55.093",
  "references": [
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/errata/RHSA-2026:0384"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/errata/RHSA-2026:0386"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/security/cve/CVE-2025-12543"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2408784"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Secondary"
    }
  ]
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2025-12543 (GCVE-0-2025-12543)

GHSA-J382-5JJ3-VW4J

FKIE_CVE-2025-12543

Tags

Sightings

Nomenclature