CVE-2026-5399: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-hvw8-fmqf-2f96
Share
CVSS 6.4
CWE-79
Published
Advisory Summary

CVE-2026-5399 is a MODERATE (CVSS 6.4) security vulnerability vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-5399 at a Glance

CVE Identifier CVE-2026-5399
GHSA Identifier GHSA-hvw8-fmqf-2f96
Severity MODERATE
CVSS v3.1 Base Score 6.4
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.4

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:L/I:L/A:N).

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 Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-5399

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-2026-5399, 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. 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 Redux Framework plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Slider field in User Profile settings in versions up to and including 4.5.13.1. This is due to insufficient input sanitization in the user_meta_save() function (which only sanitizes array values, not scalar values) and improper output escaping in the Redux_Slider::render() method, which outputs slider values into unquoted HTML attributes. The vulnerability also exploits the fact that the clean_default() method only casts values to numeric types when they are empty or out of bounds, allowing malicious strings like '1 tabindex=0 autofocus onfocus=alert(1) x=' to pass validation through PHP's loose type comparison. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary web scripts into their user profile that will execute whenever an Administrator navigates to view the attacker's profile page.

References

NVD — CVE-2026-5399 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5399
Software Source Repository REPOSITORY
https://github.com/reduxframework/redux-framework/pull/4112/changes
plugins.trac.wordpress.org/browser/redux-frame... WEB
https://plugins.trac.wordpress.org/browser/redux-framework/tags/4.5.10/redux-core/inc/extensions/users/class-redux-extension-users.php#L1018
plugins.trac.wordpress.org/browser/redux-frame... WEB
https://plugins.trac.wordpress.org/browser/redux-framework/tags/4.5.10/redux-core/inc/fields/slider/class-redux-slider.php#L311
plugins.trac.wordpress.org/browser/redux-frame... WEB
https://plugins.trac.wordpress.org/browser/redux-framework/trunk/redux-core/inc/extensions/users/class-redux-extension-users.php#L1018
plugins.trac.wordpress.org/browser/redux-frame... WEB
https://plugins.trac.wordpress.org/browser/redux-framework/trunk/redux-core/inc/fields/slider/class-redux-slider.php#L311
www.wordfence.com/threat-intel/vulner... WEB
https://www.wordfence.com/threat-intel/vulnerabilities/id/31c554cf-eee9-45a8-8fb6-198978620204?source=cve

Frequently Asked Questions

What is CVE-2026-5399?
CVE-2026-5399 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-5399?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-5399?
CVE-2026-5399 has a CVSS v3.1 base score of 6.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-5399?
CVE-2026-5399 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Maven dependencies for CVE-2026-5399?
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-hvw8-fmqf-2f96",
  "modified" : "2026-09-10T12:31:19Z",
  "published" : "2026-09-10T12:31:19Z",
  "aliases" : [ "CVE-2026-5399" ],
  "details" : "The Redux Framework plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Slider field in User Profile settings in versions up to and including 4.5.13.1. This is due to insufficient input sanitization in the user_meta_save() function (which only sanitizes array values, not scalar values) and improper output escaping in the Redux_Slider::render() method, which outputs slider values into unquoted HTML attributes. The vulnerability also exploits the fact that the clean_default() method only casts values to numeric types when they are empty or out of bounds, allowing malicious strings like '1 tabindex=0 autofocus onfocus=alert(1) x=' to pass validation through PHP's loose type comparison. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary web scripts into their user profile that will execute whenever an Administrator navigates to view the attacker's profile page.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-5399"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/reduxframework/redux-framework/pull/4112/changes"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/redux-framework/tags/4.5.10/redux-core/inc/extensions/users/class-redux-extension-users.php#L1018"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/redux-framework/tags/4.5.10/redux-core/inc/fields/slider/class-redux-slider.php#L311"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/redux-framework/trunk/redux-core/inc/extensions/users/class-redux-extension-users.php#L1018"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/browser/redux-framework/trunk/redux-core/inc/fields/slider/class-redux-slider.php#L311"
  }, {
    "type" : "WEB",
    "url" : "https://www.wordfence.com/threat-intel/vulnerabilities/id/31c554cf-eee9-45a8-8fb6-198978620204?source=cve"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-10T10:17:31Z"
  }
}