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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-55430 Detail

Description

Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the workspace app proxy resolves the target app from `httpapi.RequestHost()` which prefers the `X-Forwarded-Host` header over the real `Host` header. No middleware strips `X-Forwarded-Host` before routing and the header is not browser-forbidden so client-side JavaScript can set it on `fetch()` calls. Practical exploitation requires subdomain app routing (wildcard hostname) enabled, a victim who visits the attacker's shared app and a deployment whose upstream proxy does not strip `X-Forwarded-Host`. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 trusts `X-Forwarded-Host` only from configured trusted proxies and otherwise resolves the routing host from the verified request host. As a workaround, place an upstream reverse proxy that strips or overwrites `X-Forwarded-Host` on untrusted requests.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/coder/coder/pull/26204 GitHub, Inc. Issue Tracking  Patch 
https://github.com/coder/coder/releases/tag/v2.29.17 GitHub, Inc. Release Notes 
https://github.com/coder/coder/releases/tag/v2.32.7 GitHub, Inc. Release Notes 
https://github.com/coder/coder/releases/tag/v2.33.8 GitHub, Inc. Release Notes 
https://github.com/coder/coder/releases/tag/v2.34.2 GitHub, Inc. Release Notes 
https://github.com/coder/coder/security/advisories/GHSA-5g4w-3vw9-478w GitHub, Inc. Patch  Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-345 Insufficient Verification of Data Authenticity GitHub, Inc.  
CWE-441 Unintended Proxy or Intermediary ('Confused Deputy') GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-55430
NVD Published Date:
07/07/2026
NVD Last Modified:
07/08/2026
Source:
GitHub, Inc.