# 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.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 May 2026
- **Updated:** 20 May 2026
- **Also known as:** GHSA-88c3-g468-4jgg

## 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 (Server-Side Request Forgery)

## 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.

## Is CVE-2026-6394 being exploited?

There is no known exploitation of CVE-2026-6394 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6394 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-6394 in the wild and no public exploit code.

Affected product: wpdive Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-6394/ (Markdown: https://insights.sbomify.com/CVE-2026-6394/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6394
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6394
- OSV: https://osv.dev/vulnerability/CVE-2026-6394

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-6394/
Summaries are generated and may contain mistakes; the official description above is the record.