SSRF in Lin-Snow Ech0
CVE-2026-79671
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.003 (22.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 22.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/lin-snow/Ech0/security/advisories/GHSA-r2x7-427f-rq69 (vendor-advisory)
- www.vulncheck.com/advisories/ech0-before-ssrf-via-dns-resolution-bypass (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.