5.4
MEDIUM CVSS 3.1
CVE-2026-6394
Nexa Blocks <= 1.1.1 - Unauthenticated Blind Server-Side Request Forgery via 'demo_json_file' Parameter
Description

The Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE plugin for WordPress is vulnerable to Server-Side Request Forgery (SSRF) in versions up to and including 1.1.1. This is due to the import_demo() function accepting a user-supplied URL in the demo_json_file POST parameter and passing it directly to wp_remote_get() without any URL validation or restriction against internal or private network destinations. The nexa_blocks_nonce required for the AJAX action is publicly exposed in the HTML source of any frontend page where the plugin is active via wp_localize_script on the enqueue_block_assets hook, effectively making the nonce available to all visitors and bypassing any intended authentication barrier. This makes it possible for unauthenticated attackers to make server-side HTTP requests to arbitrary internal or external destinations, potentially exposing internal services, cloud metadata endpoints such as the AWS instance metadata service, localhost services, and other resources not intended to be publicly accessible. A secondary SSRF vector also exists whereby image URLs extracted from the attacker-controlled JSON response are subsequently fetched via a second wp_remote_get() call, allowing chained exploitation through a crafted JSON payload.

INFO

Published Date :

May 20, 2026, 2:16 a.m.

Last Modified :

May 20, 2026, 2:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-6394 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update the Nexa Blocks plugin to patch a Server-Side Request Forgery vulnerability.
  • Update the Nexa Blocks plugin to the latest version.
  • Apply vendor patches if available.
  • Restrict access to internal network resources.
  • Monitor network traffic for suspicious requests.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-6394 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-6394 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-6394 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-6394 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 20, 2026

    Action Type Old Value New Value
    Added Description The Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE plugin for WordPress is vulnerable to Server-Side Request Forgery (SSRF) in versions up to and including 1.1.1. This is due to the import_demo() function accepting a user-supplied URL in the demo_json_file POST parameter and passing it directly to wp_remote_get() without any URL validation or restriction against internal or private network destinations. The nexa_blocks_nonce required for the AJAX action is publicly exposed in the HTML source of any frontend page where the plugin is active via wp_localize_script on the enqueue_block_assets hook, effectively making the nonce available to all visitors and bypassing any intended authentication barrier. This makes it possible for unauthenticated attackers to make server-side HTTP requests to arbitrary internal or external destinations, potentially exposing internal services, cloud metadata endpoints such as the AWS instance metadata service, localhost services, and other resources not intended to be publicly accessible. A secondary SSRF vector also exists whereby image URLs extracted from the attacker-controlled JSON response are subsequently fetched via a second wp_remote_get() call, allowing chained exploitation through a crafted JSON payload.
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
    Added CWE CWE-918
    Added Reference https://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/classes/enqueue-assets.php#L84
    Added Reference https://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/template/template.php#L236
    Added Reference https://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/template/template.php#L242
    Added Reference https://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/classes/enqueue-assets.php#L84
    Added Reference https://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/template/template.php#L236
    Added Reference https://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/template/template.php#L242
    Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/b4bb3067-7953-466d-a469-8a101450f133?source=cve
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.