CVE-2026-79671: Lin-Snow ECH0

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

Ech0 before 4.4.3 contains a server-side request forgery vulnerability in the validateWebhookURL function (webhook_setting_service.go), which only validates literal IP addresses via net.ParseIP() and fails to reject hostnames that DNS-resolve to private or internal IPs (e.g., 169.254.169.254.nip.io). An attacker with admin privileges can create a webhook with such a hostname to bypass validation and cause the server to make requests to internal services, cloud metadata endpoints, and private network resources. The issue is fixed in 4.4.3.

Affected products

• Lin-Snow ECH0: before 4.4.3 (fixed in 4.4.3)

Published 2026-08-25. Last modified 2026-08-31.