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...

CVE-2026-45045

Fiber (GoFiber) is affected by a vulnerability in BalancerForward where the proxy injects X-Real-IP using Header.Add() instead of Header.Set(), allowing an attacker-supplied value to be forwarded to upstreams. Affected versions before 3.3.0 and 2.52.14 are impacted; the issue is fixed in 3.3.0 an...