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.
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.
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 | | 2.33 | v2.33.8 | | 2.32 | v2.32.7 | | 2.29 (ESR) | v2.29.17 |
Restrict the Owner role to trusted administrators.
We'd like to thank Anthropic's Security Team (ANT-2026-22453) for independently disclosing this issue!
| Software | Affected versions |
|---|---|
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 |
A vulnerability database tells you what is broken. Attack surface management tells you where it is running: it discovers your internet-facing assets and flags the ones affected by issues like this one.
What is attack surface management? →A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.