CVE-2026-55438 Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing

Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2, Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When a workspace-name subdomain segment parsed as a UUID, the...

Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing

Summary Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When a workspace-name subdomain segment parsed as a UUID, the workspace was resolved by ID without confirming the URL's username matched the real owner, while the CORS middleware trusted the...

GHSA-5WG6-JMQ2-53PW Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing

Summary Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When a workspace-name subdomain segment parsed as a UUID, the workspace was resolved by ID without confirming the URL's username matched the real owner, while the CORS middleware trusted the...