---
id: CVE-2026-55432
aliases:
  - GHSA-x9qq-2qh5-8rxf
title: >-
  Coder's sub-agent app registration bypasses template port-sharing policy
  enforcement
summary: >-
  Coder's sub-agent app registration bypasses template port-sharing policy
  enforcement
severity: medium
cvss: 5.4
cwe:
  - CWE-862
vendor: coder
product: github.com/coder/coder/v2
ecosystem: go
affected:
  - 'github.com/coder/coder/v2 >= 2.34.0, < 2.34.2'
  - 'github.com/coder/coder/v2 >= 2.33.0, < 2.33.8'
  - 'github.com/coder/coder/v2 >= 2.30.0, < 2.32.7'
  - github.com/coder/coder/v2 < 2.29.17
patched:
  - github.com/coder/coder/v2 2.34.2
  - github.com/coder/coder/v2 2.33.8
  - github.com/coder/coder/v2 2.32.7
  - github.com/coder/coder/v2 2.29.17
published: '2026-07-06'
updated: '2026-07-06'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-x9qq-2qh5-8rxf'
references:
  - url: 'https://github.com/coder/coder/security/advisories/GHSA-x9qq-2qh5-8rxf'
  - url: 'https://github.com/coder/coder/pull/26061'
  - url: 'https://github.com/advisories/GHSA-x9qq-2qh5-8rxf'
tags:
  - ghsa
  - go
ingestedAt: '2026-07-06T21:45:52.957Z'
epss: 0.00315
epssPercentile: 0.24674
---

## Overview

### Summary

The `CreateSubAgent` RPC did not validate a requested app sharing level against the template's `MaxPortSharingLevel` before persisting workspace apps, letting a workspace owner exceed the administrator's configured maximum.

> **Note:** Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls.

### Impact

A workspace owner with an agent token could register a sub-agent app as `PUBLIC` even when the template's `MaxPortSharingLevel` was `owner`, exposing the app to unauthenticated users via the wildcard app domain. This affected only deployments using Enterprise port-sharing policy and wildcard app hostnames and required an authenticated workspace owner with an agent token.

### Patches

The fix clamps the sub-agent app sharing level to the template's `MaxPortSharingLevel`.

The fix was backported to all supported release lines:

| Release line | Patched version |
|---|---|
| 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) |
| 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) |
| 2.32 | [v2.32.7](https://github.com/coder/coder/releases/tag/v2.32.7) |
| 2.29 (ESR) | [v2.29.17](https://github.com/coder/coder/releases/tag/v2.29.17) |

### Workarounds

Disable wildcard app hostnames (`CODER_WILDCARD_ACCESS_URL`) to block subdomain-based app routing.

### Resources

- Fix: #26061

### Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22452) for independently disclosing this issue!

## Affected packages

- `github.com/coder/coder/v2 >= 2.34.0, < 2.34.2`
- `github.com/coder/coder/v2 >= 2.33.0, < 2.33.8`
- `github.com/coder/coder/v2 >= 2.30.0, < 2.32.7`
- `github.com/coder/coder/v2 < 2.29.17`

## Remediation

Upgrade to a patched release:

- `github.com/coder/coder/v2 2.34.2`
- `github.com/coder/coder/v2 2.33.8`
- `github.com/coder/coder/v2 2.32.7`
- `github.com/coder/coder/v2 2.29.17`