CVE-2026-18674: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-fxcr-qwx6-5h7q
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CWE-345
Published
Advisory Summary

CVE-2026-18674 is a HIGH security vulnerability vulnerability (CWE-345: Insufficient Verification of Data Authenticity) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-18674 at a Glance

CVE Identifier CVE-2026-18674
GHSA Identifier GHSA-fxcr-qwx6-5h7q
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-345: Insufficient Verification of Data Authenticity
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-18674

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-18674, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-345: Insufficient Verification of Data Authenticity, where the product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

On a Kong Mesh global control plane, resources received over the zone-to-global KDS sync are attributed using the in-band, sender-controlled ControlPlane.Identifier rather than the authenticated zone identity derived from the connection. Authenticated zones can have the global control plane store and re-distribute those resources as belonging to another zone. The result is a cross-zone isolation bypass: the holder of a single enrolled zone's credential can inject, attribute, and overwrite resources in another zone's namespace mesh-wide. The root cause lives in Kuma's open-source KDS sync code, which Kong Mesh's control plane is built on.

References

GitHub Advisory / Wiki ADVISORY
https://github.com/kumahq/kuma/security/advisories/GHSA-m58j-fjmc-h3g4
NVD — CVE-2026-18674 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-18674
Software Source Repository REPOSITORY
https://github.com/kumahq/kuma/pull/17456
Software Source Repository REPOSITORY
https://github.com/kumahq/kuma/pull/17458
Software Source Repository REPOSITORY
https://github.com/kumahq/kuma/pull/17459
Software Source Repository REPOSITORY
https://github.com/kumahq/kuma/pull/17460
Software Source Repository REPOSITORY
https://github.com/kumahq/kuma/pull/17461
Software Source Repository REPOSITORY
https://github.com/kumahq/kuma/pull/17462
Software Source Repository REPOSITORY
https://github.com/kumahq/kuma/pull/17463
developer.konghq.com/mesh/changelog WEB
https://developer.konghq.com/mesh/changelog

Frequently Asked Questions

What is CVE-2026-18674?
CVE-2026-18674 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-345: Insufficient Verification of Data Authenticity.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-18674?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-18674?
CVE-2026-18674 is classified under CWE-345: Insufficient Verification of Data Authenticity (The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.).
How can I check Maven dependencies for CVE-2026-18674?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-fxcr-qwx6-5h7q",
  "modified" : "2026-08-17T15:30:38Z",
  "published" : "2026-08-17T15:30:38Z",
  "aliases" : [ "CVE-2026-18674" ],
  "details" : "On a Kong Mesh global control plane, resources received over the zone-to-global KDS sync are attributed using the in-band, sender-controlled ControlPlane.Identifier rather than the authenticated zone identity derived from the connection. Authenticated zones can have the global control plane store and re-distribute those resources as belonging to another zone.\n\n\n\nThe result is a cross-zone isolation bypass: the holder of a single enrolled zone's credential can inject, attribute, and overwrite resources in another zone's namespace mesh-wide.\n\n\n\n\nThe root cause lives in Kuma's open-source KDS sync code, which Kong Mesh's control plane is built on.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:H/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/security/advisories/GHSA-m58j-fjmc-h3g4"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-18674"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/pull/17456"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/pull/17458"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/pull/17459"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/pull/17460"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/pull/17461"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/pull/17462"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kumahq/kuma/pull/17463"
  }, {
    "type" : "WEB",
    "url" : "https://developer.konghq.com/mesh/changelog"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-345" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-17T13:16:51Z"
  }
}