CVE-2026-35037: ECH0

High severity, CVSS 7.2. EPSS: 0.7% chance of exploitation in the next 30 days.

Ech0 is an open-source, self-hosted publishing platform for personal idea sharing. Prior to 4.2.8, the GET /api/website/title endpoint accepts an arbitrary URL via the website_url query parameter and makes a server-side HTTP request to it without any validation of the target host or IP address. The endpoint requires no authentication. An attacker can use this to reach internal network services, cloud metadata endpoints (169.254.169.254), and localhost-bound services, with partial response data exfiltrated via the HTML <title> tag extraction This vulnerability is fixed in 4.2.8.

Affected products

• ECH0 ECH0: before 4.2.8 (fixed in 4.2.8)

Published 2026-04-06. Last modified 2026-06-17.