Vulnerability · Published Aug 25, 2026 · Assigned by VulnCheck

CVE-2026-79659Ech0 before 4.7.3 Server-Side Request Forgery via fetchPeerConnectInfo

High 7.7

In plain English

A high-severity server-side request forgery in Ech0 from lin-snow. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.7High

Exploit odds (30 days)0.4%top 70.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Ech0 before 4.7.3 contains a server-side request forgery vulnerability in the fetchPeerConnectInfo function that uses unvalidated HTTP requests instead of safe request methods with URL validation. Authenticated attackers can supply arbitrary URLs to access internal services and cloud metadata endpoints by triggering connection health checks or peer connection operations.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/lin-snow/ech0	1.4.8-0.20260503040602-091d26d2d942	GHSA-8mc6-xjpr-h98x
Go	github.com/lin-snow/ech0	1.4.8-0.20260503040602-091d26d2d942	GO-2026-5259

Affected products (as reported)

Vendor	Product	Versions
lin-snow	Ech0	0 – before 4.7.3

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

References

GitHub Security Advisory (GHSA-8mc6-xjpr-h98x) vendor-advisory
VulnCheck Advisory: Ech0 before 4.7.3 Server-Side Request Forgery via fetchPeerConnectInfo third-party-advisory