CVE-2026-79671

MEDIUM 5.5

Ech0 before 4.4.3 SSRF via DNS Resolution Bypass

CVSS Score

5.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-918
Vendor	lin-snow
Product	ech0
Published	Aug 25, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

lin-snow / Ech0

0 < 4.4.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/lin-snow/Ech0/security/advisories/GHSA-r2x7-427f-rq69 vulncheck.com: https://www.vulncheck.com/advisories/ech0-before-ssrf-via-dns-resolution-bypass

Credits

🔍 offset