CVE-2026-18438: Software Security Vulnerability Vulnerability

HIGH

Advisory Identifier: GHSA-wqqc-79qg-345q

CVSS 8.8

Published 2026-08-15

Advisory Summary

CVE-2026-18438 is a HIGH (CVSS 8.8) security vulnerability vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product allows the upload or transfer of dangerous file types that are automatically processed within its environment.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-18438 at a Glance

CVE Identifier CVE-2026-18438

GHSA Identifier GHSA-wqqc-79qg-345q

Severity HIGH

CVSS v3.1 Base Score 8.8

CWE Classification CWE-434: Unrestricted Upload of File with Dangerous Type

Affected Product Software

Package Ecosystem Maven

Published Date 2026-08-15

Last Updated 2026-08-15

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-2026-18438

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-2026-18438, 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-434: Unrestricted Upload of File with Dangerous Type, where the product allows the upload or transfer of dangerous file types that are automatically processed within its environment. 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 Templately – Elementor & Gutenberg Template Library: 6500+ Free & Pro Ready Templates And Cloud! plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 3.7.1 via the fetch_remote_file function. This is due to a filename validation/destination mismatch in fetch_remote_file, where file type validation is performed against the attacker-controlled Content-Disposition filename rather than the URL-path-derived destination filename. This makes it possible for authenticated attackers, with contributor-level access and above, to execute code on the server. A GIF+PHP polyglot file passes wp_check_filetype_and_ext validation as image/gif via the Content-Disposition filename, while the actual destination path is written with a .php extension derived from the URL path, bypassing the unfiltered_upload capability gate entirely. The affected endpoints are reachable at this privilege level because Templately's entire REST API — including the cloud import endpoints used in this attack (/templately/v1/clouds/upload and /templately/v1/insert) — is authorized only by a current_user_can('delete_posts') check, with no administrator or manage_options capability requirement. The same permission gate also allows a contributor to overwrite the site's global Templately cloud connection via the /templately/v1/login endpoint with global_signin set to true. A complete remediation should both correct fetch_remote_file to validate the file type against the actual destination filename rather than the Content-Disposition header (and avoid deriving the write path from the request URL), and restrict state-changing Templately REST routes to an appropriate administrator-level capability.

References

NVD — CVE-2026-18438 NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-18438

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.6.5/includes/API/API.php#L128

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.6.5/includes/API/Import.php#L78

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.6.5/includes/API/MyClouds.php#L103

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.6.5/includes/Core/Importer/WPImport.php#L1200

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.6.5/includes/Core/Importer/WPImport.php#L1391

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.6.5/includes/Core/Importer/WPImport.php#L1423

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.6.5/includes/Core/Platform/Gutenberg.php#L177

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/API/API.php#L128

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/API/Import.php#L78

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/API/MyClouds.php#L103

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/Core/Importer/WPImport.php#L1200

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/Core/Importer/WPImport.php#L1391

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/Core/Importer/WPImport.php#L1423

plugins.trac.wordpress.org/browser/templately/... WEB

https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/Core/Platform/Gutenberg.php#L177

plugins.trac.wordpress.org/changeset/3636643/t... WEB

https://plugins.trac.wordpress.org/changeset/3636643/templately/trunk/includes/Core/Importer/WPImport.php

plugins.trac.wordpress.org/changeset WEB

https://plugins.trac.wordpress.org/changeset?old_path=%2Ftemplately/tags/3.7.1&new_path=%2Ftemplately/tags/3.7.2

plugins.trac.wordpress.org/changeset WEB

https://plugins.trac.wordpress.org/changeset?reponame=&new=3636643%40templately%2Ftags%2F3.7.2&old=3624408%40templately%2Ftags%2F3.7.1

www.wordfence.com/threat-intel/vulner... WEB

https://www.wordfence.com/threat-intel/vulnerabilities/id/4e68b2f2-12e4-4ff2-919d-26d6b21acd03?source=cve

Frequently Asked Questions

What is CVE-2026-18438?

CVE-2026-18438 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-434: Unrestricted Upload of File with Dangerous Type.

Which Software versions are affected?

Affected versions include releases prior to current release patches.

What version fixes CVE-2026-18438?

Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.

What is the CVSS score of CVE-2026-18438?

CVE-2026-18438 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-2026-18438?

CVE-2026-18438 is classified under CWE-434: Unrestricted Upload of File with Dangerous Type (The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.).

How can I check Maven dependencies for CVE-2026-18438?

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-wqqc-79qg-345q",
  "modified" : "2026-08-15T12:30:19Z",
  "published" : "2026-08-15T12:30:19Z",
  "aliases" : [ "CVE-2026-18438" ],
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  "severity" : [ {
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  }, {
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    "url" : "https://plugins.trac.wordpress.org/browser/templately/tags/3.7.1/includes/Core/Platform/Gutenberg.php#L177"
  }, {
    "type" : "WEB",
    "url" : "https://plugins.trac.wordpress.org/changeset/3636643/templately/trunk/includes/Core/Importer/WPImport.php"
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  }, {
    "type" : "WEB",
    "url" : "https://www.wordfence.com/threat-intel/vulnerabilities/id/4e68b2f2-12e4-4ff2-919d-26d6b21acd03?source=cve"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-434" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-15T10:16:29Z"
  }
}

CVSS V3

8.8 HIGH

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)

Vector String

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Advisory Metadata

Source ID: GHSA-wqqc-79qg-345q
Schema Version: 1.4.0
Published: 2026-08-15 12:30
Last Modified: 2026-08-15 12:30
Database Record File: advisories/unreviewed/2026/08/GHSA-wqqc-79qg-345q/GHSA-wqqc-79qg-345q.json