CVE-2026-55438

Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing. Prior to versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2, subdomain-based proxy would bypass the same-owner CORS check when a workspace-name segment parsed as a UUID. The workspace could be resolved by ID with...

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...

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...

CVE-2026-55432 Coder's sub-agent app registration bypasses template port-sharing policy enforcement

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 CreateSubAgent RPC did not validate a requested app sharing level against the template's MaxPortSharingLevel before persisting workspace apps, letting a...

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...

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...

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, 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...

CVE-2026-55430

Coder's workspace app (github.com/coder/coder) prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 trusts X-Forwarded-Host for routing because no middleware strips it before routing and httpapi.RequestHost() prefers that header over Host. This enables cross-app data access when subdomain (wildca...

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...

GO-2026-5917 Coder's subdomain workspace app routing trusts unauthenticated X-Forwarded-Host header, enabling cross-app data access in github.com/coder/coder

Coder's subdomain workspace app routing trusts unauthenticated X-Forwarded-Host header, enabling cross-app data access in github.com/coder/coder...

GO-2026-5918 Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing in github.com/coder/coder

Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing in github.com/coder/coder...

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...

Origin Validation Error

Overview Affected versions of this package are vulnerable to Origin Validation Error via the CORS origin validation process. An attacker can gain unauthorized access to sensitive data by crafting a subdomain that encodes their own workspace UUID and a victim's username, then tricking an...

Origin Validation Error

Overview Affected versions of this package are vulnerable to Origin Validation Error via the CORS origin validation process. An attacker can gain unauthorized access to sensitive data by crafting a subdomain that encodes their own workspace UUID and a victim's username, then tricking an...

Origin Validation Error

Overview Affected versions of this package are vulnerable to Origin Validation Error via the CORS origin validation process. An attacker can gain unauthorized access to sensitive data by crafting a subdomain that encodes their own workspace UUID and a victim's username, then tricking an...

Origin Validation Error

Overview Affected versions of this package are vulnerable to Origin Validation Error via the CORS origin validation process. An attacker can gain unauthorized access to sensitive data by crafting a subdomain that encodes their own workspace UUID and a victim's username, then tricking an...

Unintended Proxy or Intermediary ('Confused Deputy')

Overview Affected versions of this package are vulnerable to Unintended Proxy or Intermediary 'Confused Deputy' in the httpapi.RequestHost process. An attacker can gain unauthorized access to sensitive data by sending requests with a crafted X-Forwarded-Host header, which is trusted over the real...

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

Summary 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...

Unintended Proxy or Intermediary ('Confused Deputy')

Overview Affected versions of this package are vulnerable to Unintended Proxy or Intermediary 'Confused Deputy' in the httpapi.RequestHost process. An attacker can gain unauthorized access to sensitive data by sending requests with a crafted X-Forwarded-Host header, which is trusted over the real...