CVE-2026-87741: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-3h53-mhw6-2896
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CVSS 8.8
CWE-78
Published
Advisory Summary

CVE-2026-87741 is a HIGH (CVSS 8.8) security vulnerability vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product constructs all or part of an os command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended os command when it is sent to a downstream component.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-87741 at a Glance

CVE Identifier CVE-2026-87741
GHSA Identifier GHSA-3h53-mhw6-2896
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.8

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:U/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 Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-87741

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-2026-87741, 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-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), where the product constructs all or part of an os command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended os command when it is sent to a downstream component. 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 ConvertPlus plugin for WordPress is vulnerable to Deserialization of Untrusted Data in all versions up to, and including, 3.6.3 via the style parameter of the cp_display_preview_modal AJAX action. The vulnerability exists because the action's nonce guard is gated behind an isset() check and fails open when the cp_admin_page_nonce parameter is omitted entirely, no capability check is performed on the callback, and sanitize_text_field() — applied to the $style value before it is concatenated directly into a shortcode string evaluated by do_shortcode() — does not strip shortcode delimiters, allowing an attacker to inject a second, fully attacker-controlled [smile_modal] invocation that causes smile_modal_popup() to pass attacker-supplied base64-decoded bytes to maybe_unserialize() with no allowed_classes restriction. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a PHP object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.

References

NVD — CVE-2026-87741 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-87741
convertpro.net WEB
https://convertpro.net
www.wordfence.com/threat-intel/vulner... WEB
https://www.wordfence.com/threat-intel/vulnerabilities/id/286b4dde-974d-4bb5-8a7e-57c849beaab1?source=cve

Frequently Asked Questions

What is CVE-2026-87741?
CVE-2026-87741 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-87741?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-87741?
CVE-2026-87741 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-87741?
CVE-2026-87741 is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.).
How can I check Maven dependencies for CVE-2026-87741?
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-3h53-mhw6-2896",
  "modified" : "2026-09-28T21:31:18Z",
  "published" : "2026-09-28T21:31:18Z",
  "aliases" : [ "CVE-2026-87741" ],
  "details" : "The ConvertPlus plugin for WordPress is vulnerable to Deserialization of Untrusted Data in all versions up to, and including, 3.6.3 via the style parameter of the cp_display_preview_modal AJAX action. The vulnerability exists because the action's nonce guard is gated behind an isset() check and fails open when the cp_admin_page_nonce parameter is omitted entirely, no capability check is performed on the callback, and sanitize_text_field() — applied to the $style value before it is concatenated directly into a shortcode string evaluated by do_shortcode() — does not strip shortcode delimiters, allowing an attacker to inject a second, fully attacker-controlled [smile_modal] invocation that causes smile_modal_popup() to pass attacker-supplied base64-decoded bytes to maybe_unserialize() with no allowed_classes restriction. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a PHP object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-87741"
  }, {
    "type" : "WEB",
    "url" : "https://convertpro.net"
  }, {
    "type" : "WEB",
    "url" : "https://www.wordfence.com/threat-intel/vulnerabilities/id/286b4dde-974d-4bb5-8a7e-57c849beaab1?source=cve"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-28T20:17:11Z"
  }
}