6.8

CVE-2026-55430

Coder's subdomain workspace app routing trusts unauthenticated X-Forwarded-Host header, enabling cross-app data access

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Coder ≫ Coder SwPlatformgo Version < 2.29.17
Coder ≫ Coder SwPlatformgo Version >= 2.30.0 < 2.32.7
Coder ≫ Coder SwPlatformgo Version >= 2.33.0 < 2.33.8
Coder ≫ Coder SwPlatformgo Version >= 2.34.0 < 2.34.2
VulnDex Vulnerability Enrichment
Diese Information steht angemeldeten Benutzern zur Verfügung. Login Login
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.14% 0.038
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
NIST 6.8 2.3 4
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N
security-advisories@github.com 5.8 1.3 4
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N
CWE-345 Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

CWE-441 Unintended Proxy or Intermediary ('Confused Deputy')

The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product's control sphere. This causes the product to appear to be the source of the request, leading it to act as a proxy or other intermediary between the upstream component and the external actor.

https://github.com/coder/coder/releases/tag/v2.32.7
Release Notes
https://github.com/coder/coder/releases/tag/v2.33.8
Release Notes
https://github.com/coder/coder/releases/tag/v2.34.2
Release Notes
https://github.com/coder/coder/releases/tag/v2.29.17
Release Notes
https://github.com/coder/coder/security/advisories/GHSA-5g4w-3vw9-478w
Patch
Vendor Advisory
https://github.com/coder/coder/pull/26204
Patch
Issue Tracking