CVE-2026-45045 Fiber: X-Real-IP Spoofing via Header.Add() in BalancerForward

Fiber is an Express inspired web framework written in Go. Prior to 3.3.0 and 2.52.14, the BalancerForward proxy helper in middleware/proxy/proxy.go uses Header.Add instead of Header.Set when injecting X-Real-IP, allowing an attacker-supplied first X-Real-IP value to be forwarded to upstream serve...