Echo: Reverse Proxy Forwards Attacker-Supplied X-Real-IP to Upstream by Default

影響: go:github.com/labstack/echo/v5 < 5.4.0 → 5.4.0, go:github.com/labstack/echo/v4 >= 4.0.0, <= 4.16.2

The Echo proxy middleware (middleware/proxy.go) preserves an incoming X-Real-IP header verbatim and forwards it to the upstream service when Echo#IPExtractor is not configured — which is the default. Because any HTTP client can supply an arbitrary X-Real-IP value, an attacker can cause Echo to relay a spoofed client IP address to every upstream service behind the proxy, undermining upstream IP-based access controls, rate limiting, audit logging, and geo-restriction. Affected Component - middlew…

Read on GitHub Advisory Database

On 10/29/2026, 04:53 AM, GitHub Advisory Database published "Echo: Reverse Proxy Forwards Attacker-Supplied X-Real-IP to Upstream by Default" (type: Advisory). Severity is "Medium" (medium). Related technologies: Go, GitHub. CVE: CVE-2026-118651.