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Vulnerability · Published May 20, 2026 · Assigned by Wordfence

CVE-2026-6394Nexa Blocks <= 1.1.1 - Unauthenticated Blind Server-Side Request Forgery via 'demo_json_file' Parameter

Medium 5.4

In plain English

A medium-severity server-side request forgery in Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE from wpdive. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 75.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

VendorProductVersions
wpdive Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE 0 – through 1.1.1

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

References