---
id: CVE-2026-111927
title: Coder before 2.35.4 Credential Theft via Workspace Proxy Hostname Prefix Match
summary: >-
  Coder before 2.29.20, 2.33.0 before 2.33.12, 2.34.0 before 2.34.8, and 2.35.0
  before 2.35.4 contains an improper hostname validation flaw in
  GetWorkspaceProxyByHostname whose SIMILAR TO pattern performs a prefix match,
  so any domain that…
severity: high
cvss: 7.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N'
cvssSource: cna
cwe:
  - CWE-522
vendor: coder
product: coder
affected:
  - coder >= 2.35.0 < 2.35.4
  - coder >= 2.34.0 < 2.34.8
  - coder >= 2.33.0 < 2.33.12
  - coder < 2.29.20
published: '2026-10-17'
updated: '2026-10-17'
sourceUpdated: '2026-10-17T18:46:39.347Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-111927'
references:
  - url: 'https://github.com/coder/coder/security/advisories/GHSA-h58h-qvv5-xvwg'
    label: GitHub Security Advisory (GHSA-h58h-qvv5-xvwg)
  - url: >-
      https://www.vulncheck.com/advisories/coder-before-2.35.4-credential-theft-via-workspace-proxy-hostname-prefix-match
    label: >-
      VulnCheck Advisory: Coder before 2.35.4 Credential Theft via Workspace
      Proxy Hostname Prefix Match
tags:
  - cve.org
ingestedAt: '2026-10-17T19:08:56.476Z'
---

## Overview

Coder before 2.29.20, 2.33.0 before 2.33.12, 2.34.0 before 2.34.8, and 2.35.0 before 2.35.4 contains an improper hostname validation flaw in GetWorkspaceProxyByHostname whose SIMILAR TO pattern performs a prefix match, so any domain that is a string prefix of a workspace-proxy access URL is trusted as a proxy. Attackers owning such a domain can lure an authenticated victim to a crafted /api/v2/applications/auth-redirect link, capture the redirected application_connect API key, and replay it to access the victim's workspace apps.

## Affected

- `coder >= 2.35.0 < 2.35.4`
- `coder >= 2.34.0 < 2.34.8`
- `coder >= 2.33.0 < 2.33.12`
- `coder < 2.29.20`

## Remediation

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