CVE-2026-6394 Nexa Blocks <= 1.1.1 - Unauthenticated Blind Server-Side Request Forgery via 'demo_json_file' Parameter
Unauthenticated attackers can exploit SSRF in Nexa Blocks to access internal services and cloud metadata via exposed nonces and unvalidated URL parameters.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-6394?
CVE-2026-6394 is a medium-severity server-side request forgery vulnerability in wpdive Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE, published on 20 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-6394?
How do I fix CVE-2026-6394?
No fix has been published for CVE-2026-6394 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-6394 being exploited?
There is no known exploitation of CVE-2026-6394 in the wild and no public exploit code.
Sources
Also known as GHSA-88c3-g468-4jgg.