CVE-2026-15827: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-phq4-ggcm-gj84
CVSS 5.3
CWE-862
Published
Advisory Summary

CVE-2026-15827 is a MODERATE (CVSS 5.3) security vulnerability vulnerability (CWE-862: Missing Authorization) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not perform an authorization check when an actor attempts to access a resource or perform an action.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-15827 at a Glance

CVE Identifier CVE-2026-15827
GHSA Identifier GHSA-phq4-ggcm-gj84
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-862: Missing Authorization
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.3

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

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

How to Fix CVE-2026-15827

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-2026-15827, 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-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. 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

The GutenKit Blocks plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the /wp-json/gutenkit/v1/mailchimp/get/lists and /wp-json/gutenkit/v1/mailchimp/get/interests REST API endpoints in versions up to, and including, 2.4.12. Both endpoints are registered with permission_callback => '__return_true', and their callbacks read the site's stored Mailchimp API key from the gutenkit_settings_list option and proxy Mailchimp audience/list, merge-field, interest-category, interest-name, and subscriber-count metadata back to the caller with no login, nonce, or capability check. This makes it possible for unauthenticated attackers to retrieve private Mailchimp audience configuration information from any site that has configured the GutenKit Mailchimp integration.

References

NVD — CVE-2026-15827 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-15827
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L141
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L17
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L43
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L62
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L141
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L17
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L43
plugins.trac.wordpress.org/browser/gutenkit-bl... WEB
https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L62
plugins.trac.wordpress.org/changeset WEB
https://plugins.trac.wordpress.org/changeset?reponame=&old=3618270%40gutenkit-blocks-addon&new=3618270%40gutenkit-blocks-addon
www.wordfence.com/threat-intel/vulner... WEB
https://www.wordfence.com/threat-intel/vulnerabilities/id/7430594c-3a71-4b24-875b-014e03be868f?source=cve

Frequently Asked Questions

What is CVE-2026-15827?
CVE-2026-15827 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-862: Missing Authorization.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-15827?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-15827?
CVE-2026-15827 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-15827?
CVE-2026-15827 is classified under CWE-862: Missing Authorization (The product does not perform an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Maven dependencies for CVE-2026-15827?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-phq4-ggcm-gj84",
  "modified" : "2026-07-23T12:32:22Z",
  "published" : "2026-07-23T12:32:22Z",
  "aliases" : [ "CVE-2026-15827" ],
  "details" : "The GutenKit Blocks plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the /wp-json/gutenkit/v1/mailchimp/get/lists and /wp-json/gutenkit/v1/mailchimp/get/interests REST API endpoints in versions up to, and including, 2.4.12. Both endpoints are registered with permission_callback => '__return_true', and their callbacks read the site's stored Mailchimp API key from the gutenkit_settings_list option and proxy Mailchimp audience/list, merge-field, interest-category, interest-name, and subscriber-count metadata back to the caller with no login, nonce, or capability check. This makes it possible for unauthenticated attackers to retrieve private Mailchimp audience configuration information from any site that has configured the GutenKit Mailchimp integration.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-15827"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L141"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L17"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L43"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.11/includes/Routes/MailChimp.php#L62"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L141"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L17"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L43"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/gutenkit-blocks-addon/tags/2.4.6/includes/Routes/MailChimp.php#L62"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/changeset?reponame=&old=3618270%40gutenkit-blocks-addon&new=3618270%40gutenkit-blocks-addon"
  }, {
    "type" : "WEB",
    "url" : "https://www.wordfence.com/threat-intel/vulnerabilities/id/7430594c-3a71-4b24-875b-014e03be868f?source=cve"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-23T10:16:51Z"
  }
}