medium5.3
CVE-2026-45045
GoFiber Vulnerable to X-Real-IP Spoofing via Header.Add() in BalancerForward
Impact
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 servers for logging, rate limiting, and access control. This issue is fixed in version 3.3.0 and 2.52.14.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/gofiber/fiber/v3 | <= 3.2.0 | 3.3.0 |
| go | github.com/gofiber/fiber/v2 | <= 2.52.13 | 2.52.14 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Gofiber | Fiber | before 2.52.14 from 3.0.0 before 3.3.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-gcfq-8gqf-4876
- https://github.com/gofiber/fiber/security/advisories/GHSA-gcfq-8gqf-4876
- https://nvd.nist.gov/vuln/detail/CVE-2026-45045
- https://github.com/gofiber/fiber/pull/4260
- https://github.com/gofiber/fiber/pull/4495
- https://github.com/gofiber/fiber/commit/1403cc8292da3220e9316960b4030cc722a0f396
- https://github.com/gofiber/fiber/commit/33c9501288ab47a429c8b5e701493f0c3c0af37d
- https://github.com/gofiber/fiber/releases/tag/v2.52.14
- https://github.com/gofiber/fiber/releases/tag/v3.3.0