Nexa Blocks <= 1.1.1 - Unauthenticated Blind Server-Side Request Forgery via 'demo_json_file' Parameter
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 software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| WordPress plugin | Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE | <= 1.1.1 | no fix |
References
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-918- Platform
- WordPress
- Package
Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE- Disclosed
- 19.05.2026
- Updated
- 11.10.2026 10:23
Sources and licenses
Wordfence Intelligence - b4bb3067-7953-466d-a469-8a101450f133 - Wordfence Intelligence
Copyright 1999-2026 The MITRE Corporation
Copyright 2012-2026 Defiant Inc.
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Vulnerability history: Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE
All published vulnerabilities of this package (WordPress plugin), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 5
- First → latest
- 06.2025 05.2026
- Without a fix
- 4
- Exploited in attacks
- 0
Severity breakdown
- High 1
- Medium 4
Disclosures per year
- 2025: 3
- 2026: 2
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Nexa Blocks <= 1.1.1 - Unauthenticated Blind Server-Side Request Forgery via 'demo_json_file' Parameter this entry
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