CVE-2026-54162

Vulnerability Description

Ember is a real-time terminal dashboard for Caddy servers with FrankenPHP support. Prior to 1.4.2, interactive TUI row formatters pass Caddy access-log fields, particularly the request URI, through the `fitCellLeft` render helper without neutralizing terminal escape or control sequences. An unauthenticated remote client can place ANSI, OSC, or CSI control bytes in an ordinary HTTP request target. Caddy JSON-escapes those bytes, `ParseLogLine` decodes them back into raw controls, and the formatters concatenate them into `View()` output reaching `os.Stdout`. When the operator views the default `Logs` tab, the terminal interprets these sequences, allowing monitoring-dashboard spoofing, clipboard hijacking through `OSC 52`, and window-title spoofing through `OSC 0/2`. This works even with a loopback-only log listener because the input arrives through normal Caddy access logs. `Certificates` and `Routes` share secondary unneutralized render sinks. The `--json`, `--once`, and daemon `--expose` modes are unaffected because they do not render an interactive terminal. Consequences depend on the terminal emulator and usually require further operator action to escalate; this is not general-purpose remote code execution. This issue is fixed in version 1.4.2.

CVSS Score

Related Weaknesses (CWE)

References

• https://github.com/alexandre-daubois/ember/commit/fcb7160e58dba58d6f9b5033cc312f
• https://github.com/alexandre-daubois/ember/releases/tag/v1.4.2
• https://github.com/alexandre-daubois/ember/security/advisories/GHSA-x3g7-qrwc-f6