GHSA-h58c-xccx-75m3 — Coder: Stored HTML injection via unescaped ApplicationName

Quick fix

GHSA-h58c-xccx-75m3 — github.com/coder/coder/v2: upgrade to the fixed version with the command below.

go get github.com/coder/coder/v2@v2.34.2

Details

### Summary

The `ApplicationName` and `LogoURL` appearance settings were rendered into HTML output without sufficient escaping which let a highly privileged Owner-role user inject HTML into the Coder dashboard and SMTP notification emails.

> **Note:** Exploitation requires the `Owner` role which already holds full administrative control of the deployment so practical impact is limited.

### Impact

An Owner-role user could store HTML markup in the `ApplicationName` or `LogoURL` appearance settings that later rendered in the dashboard and in SMTP notification emails which results in stored HTML injection against other users of the deployment. Exploitation requires the highly privileged `Owner` role.

### Patches

The fix escapes the `ApplicationName` and `LogoURL` appearance values in HTML output before rendering.

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

Restrict the `Owner` role to trusted administrators.

### References

- Fix: #25804

### Credits

We'd like to thank Anthropic's Security Team (ANT-2026-22453) for independently disclosing this issue!