SSRF in Lin-Snow Ech0
CVE-2026-79671
Ech0 through 4.2.1 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.
Vulnerability class: SSRF (Server-Side Request Forgery)
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-79671?
- CVE-2026-79671 is a medium-severity vulnerability in Lin-Snow Ech0, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.5/10. Published 2026-08-25.
- How severe is CVE-2026-79671?
- Medium severity. CVSS v3 base score is 5.5 out of 10.