---
id: CVE-2026-111934
title: Coder before 2.34.7 IP Spoofing via X-Forwarded-For Header
summary: >-
  Coder before 2.34.7 contains an IP spoofing vulnerability in the
  ExtractRealIPAddress middleware that trusts the leftmost, client-supplied
  X-Forwarded-For value instead of the client IP appended by a reverse proxy.
  Attackers can send for…
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-348
vendor: coder
product: coder
affected:
  - coder < 2.34.7
published: '2026-10-17'
updated: '2026-10-17'
sourceUpdated: '2026-10-17T18:46:44.142Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-111934'
references:
  - url: 'https://github.com/coder/coder/security/advisories/GHSA-vprw-xcrv-287h'
    label: GitHub Security Advisory (GHSA-vprw-xcrv-287h)
  - url: >-
      https://www.vulncheck.com/advisories/coder-before-2.34.7-ip-spoofing-via-x-forwarded-for-header
    label: >-
      VulnCheck Advisory: Coder before 2.34.7 IP Spoofing via X-Forwarded-For
      Header
tags:
  - cve.org
ingestedAt: '2026-10-17T19:08:56.501Z'
---

## Overview

Coder before 2.34.7 contains an IP spoofing vulnerability in the ExtractRealIPAddress middleware that trusts the leftmost, client-supplied X-Forwarded-For value instead of the client IP appended by a reverse proxy. Attackers can send forged X-Forwarded-For values through appending proxies to bypass per-IP rate limits on login, one-time passcode, and password validation endpoints, enabling brute-force attacks, and to falsify IP addresses recorded in audit logs.

## Affected

- `coder < 2.34.7`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.