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…

GitHub Advisory Databaseで読む

2026/10/29 04:53、GitHub Advisory Databaseが「Echo: Reverse Proxy Forwards Attacker-Supplied X-Real-IP to Upstream by Default」を公開しました (種別: 脆弱性アドバイザリ)。重大度は「警告」(medium) です。関連する技術: Go、GitHub。CVE: CVE-2026-118651。