CVE-2026-66788: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-264j-8377-4hmm
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CVSS 9.9
CWE-1104 CWE-284
Published
Advisory Summary

CVE-2026-66788 is a CRITICAL (CVSS 9.9) security vulnerability vulnerability (CWE-1104: Use of Unmaintained Third Party Components) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-66788 at a Glance

CVE Identifier CVE-2026-66788
GHSA Identifier GHSA-264j-8377-4hmm
Severity CRITICAL
CVSS v3.1 Base Score 9.9
CWE Classification CWE-1104: Use of Unmaintained Third Party Components
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-66788

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-2026-66788, 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-1104: Use of Unmaintained Third Party Components, where the product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer. 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

A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.

References

NVD — CVE-2026-66788 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66788
access.redhat.com/errata/rhsa-2026:63... WEB
https://access.redhat.com/errata/RHSA-2026:63016
access.redhat.com/errata/rhsa-2026:85... WEB
https://access.redhat.com/errata/RHSA-2026:85227
Software Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-66788
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2507533

Frequently Asked Questions

What is CVE-2026-66788?
CVE-2026-66788 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-1104: Use of Unmaintained Third Party Components.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-66788?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-66788?
CVE-2026-66788 has a CVSS v3.1 base score of 9.9 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2026-66788?
CVE-2026-66788 is classified under CWE-1104: Use of Unmaintained Third Party Components (The product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer.).
How can I check Maven dependencies for CVE-2026-66788?
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-264j-8377-4hmm",
  "modified" : "2026-10-19T18:32:00Z",
  "published" : "2026-08-20T21:31:28Z",
  "aliases" : [ "CVE-2026-66788" ],
  "details" : "A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-66788"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:63016"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:85227"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-66788"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2507533"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1104", "CWE-284" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-20T19:16:58Z"
  }
}