CVE-2026-46393 Overview
CVE-2026-46393 is an authenticated Server-Side Request Forgery (SSRF) vulnerability in HAX CMS, a content management system that manages microsite networks with PHP or NodeJS backends. The vulnerability affects all versions prior to 26.0.0 and allows authenticated users to force the server to fetch arbitrary internal or local resources. The fetched responses are written to a web-accessible directory, which converts the SSRF primitive into an arbitrary file read and exposes internal network services. The flaw is tracked under CWE-918: Server-Side Request Forgery.
Critical Impact
Authenticated attackers can read internal files and pivot into internal network services by abusing the server-side fetch functionality and retrieving responses from a web-accessible directory.
Affected Products
- HAX CMS PHP backend versions prior to 26.0.0
- HAX CMS NodeJS backend versions prior to 26.0.0
- HAX CMS microsite deployments hosting authenticated user accounts
Discovery Timeline
- 2026-06-05 - CVE-2026-46393 published to NVD
- 2026-06-08 - Last updated in NVD database
Technical Details for CVE-2026-46393
Vulnerability Analysis
The vulnerability resides in a server-side fetch routine accessible to authenticated HAX CMS users. The application accepts a URL parameter and issues an outbound HTTP request without validating the target host or scheme. The server then writes the response body into a directory served by the web root. This design transforms a standard SSRF into a two-stage primitive that yields full response content rather than blind interactions.
Attackers with valid credentials can request http://127.0.0.1, http://169.254.169.254/latest/meta-data/, or file:// style targets depending on the backend HTTP client. The retrieved content lands in a predictable web-accessible path, allowing the attacker to read it over HTTPS from outside the network boundary. See the GitHub Security Advisory GHSA-q862-gcgq-5m6g for vendor details.
Root Cause
The root cause is missing validation of user-supplied URLs in the server-side fetch handler. The backend does not enforce an allowlist of hostnames, does not block private IP ranges (RFC 1918, loopback, link-local), and does not restrict URL schemes. Combined with writing the response into a web-accessible directory, the issue elevates from blind SSRF to full content disclosure.
Attack Vector
The attack requires network access to the HAX CMS interface and a valid authenticated session with low privileges. An attacker submits a crafted request to the vulnerable endpoint specifying an internal target URL. The server fetches the resource, stores the response under the public asset directory, and the attacker retrieves the saved file directly over HTTP. This workflow enables reconnaissance of internal services, cloud metadata theft, and reading of local files reachable by the application user.
Detection Methods for CVE-2026-46393
Indicators of Compromise
- Outbound HTTP requests from the HAX CMS server to internal RFC 1918 addresses, 127.0.0.1, or 169.254.169.254
- New or unexpected files written under the HAX CMS public asset directory containing HTML, JSON, or binary content not associated with normal site assets
- Authenticated API calls targeting the URL-fetch endpoint with non-HTTPS schemes such as file://, gopher://, or dict://
- Repeated fetch requests from a single user account enumerating sequential internal IPs or ports
Detection Strategies
- Inspect web server access logs for authenticated requests to the HAX CMS fetch endpoint paired with internal hostnames in query parameters
- Correlate process-level network telemetry with HTTP requests to the CMS to identify SSRF-driven outbound traffic from the PHP-FPM or Node.js process
- Hunt for unexpected file writes under the web root performed by the HAX CMS service account
- Alert on responses from cloud metadata endpoints originating from the CMS host
Monitoring Recommendations
- Forward web server, application, and egress firewall logs to a centralized data lake for cross-source correlation
- Monitor egress traffic from the CMS host with deny-by-default rules for private address ranges
- Track file creation events in the public asset directory and baseline normal upload patterns
- Review authentication logs for low-privilege accounts that suddenly increase fetch endpoint usage
How to Mitigate CVE-2026-46393
Immediate Actions Required
- Upgrade HAX CMS to version 26.0.0 or later, which contains the official fix
- Audit the public asset directory for unexpected files that may contain exfiltrated internal data
- Rotate any secrets, cloud instance credentials, or API tokens that the CMS host could reach via SSRF
- Review authenticated user accounts and disable any that appear unused or unauthorized
Patch Information
The maintainers released HAX CMS version 26.0.0 to address CVE-2026-46393. Administrators should follow the upgrade procedure documented in the GitHub Security Advisory GHSA-q862-gcgq-5m6g and validate that both PHP and NodeJS backends are updated where deployed.
Workarounds
- Restrict egress traffic from the HAX CMS host so it cannot reach loopback, link-local, or RFC 1918 ranges except for required dependencies
- Place the CMS behind an egress proxy that enforces an allowlist of permitted destination hosts
- Tighten authentication and limit account creation until the patch is applied to reduce the population of users who can trigger the fetch endpoint
- Remove or relocate the writable public asset directory mapping until upgrade is complete to prevent retrieval of fetched content
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
