CVE-2026-45045 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-45045MEDIUM

gofiber fiber — Fiber: X-Real-IP Spoofing via Header.Add() in BalancerForward

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  L  N    5.3   .0036   29.6     —

AFFECTED
  Product  Versions                    Fixed
  fiber    >= 3.0.0-beta.2, < 3.3.0 –  —

TIMELINE
  May 8   Reserved by GitHub_M
  Jul 8   EXPLOIT PUBLISHED — CVE-2026-45045 (gofiber fiber). Public exploit reference added.
  Jul 8   Published (CNA: GitHub_M)

CWE-290 · CNA: GitHub_M · CVSS v3.1 · 7 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 8, 2026	Reserved	Reserved by GitHub_M
July 8, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-45045 (gofiber fiber). Public exploit reference added.
July 8, 2026	Published	Published (CNA: GitHub_M)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
gofiber	fiber	—	>= 3.0.0-beta.2, < 3.3.0	—

Weaknesses

CWE-290

References (7)

https://github.com/gofiber/fiber/commit/1403cc8292da3220e9316960b4030cc722a0f396 [Patch]
https://github.com/gofiber/fiber/commit/33c9501288ab47a429c8b5e701493f0c3c0af37d [Patch]
https://github.com/gofiber/fiber/pull/4260 [Issue Tracking, Patch]
https://github.com/gofiber/fiber/pull/4495 [Issue Tracking, Patch]
https://github.com/gofiber/fiber/releases/tag/v2.52.14 [Release Notes]
https://github.com/gofiber/fiber/releases/tag/v3.3.0 [Release Notes]
https://github.com/gofiber/fiber/security/advisories/GHSA-gcfq-8gqf-4876 [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-45045 at cve.org

Vendors: gofiber

Weaknesses: CWE-290

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-45045 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.