CVE-2026-55430
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,
CVSS
5.8
Medio
EPSS
0.2%
p11
KEV
—
Exploit Today
3
0-100
Publicado: 8 jul 2026 · Última mod.: 8 jul 2026 · CWE-345 · CWE-441
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.
- github.comhttps://github.com/coder/coder/pull/26204
- github.comhttps://github.com/coder/coder/releases/tag/v2.29.17
- github.comhttps://github.com/coder/coder/releases/tag/v2.32.7
- github.comhttps://github.com/coder/coder/releases/tag/v2.33.8
- github.comhttps://github.com/coder/coder/releases/tag/v2.34.2
- github.comhttps://github.com/coder/coder/security/advisories/GHSA-5g4w-3vw9-478w