CVE-2026-75520 Domoticz: Missing authorization and path traversal in the udevices Lua parser handler
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-75520?
CVE-2026-75520 is a medium-severity vulnerability in domoticz, published on 28 Oct 2026.
Official description
Domoticz is a free, open source home automation system for Linux, Windows, macOS, and Raspberry Pi. Prior to 2026.3, the `udevices` JSON command handler, `Cmd_UpdateDevices` in `main/WebServerCmds.cpp`, performed no `session.rights` check before invoking a Lua parser script, while its sibling command handlers gate access by role. A low-privilege authenticated user could trigger execution of an existing operator-installed Lua parser script with attacker-controlled input through the `GET /json.htm` endpoint with `type=command` and `param=udevices`. The `script` parameter also lacked a `..` path-traversal guard: `CLuaHandler::executeLuaScript` in `main/LuaHandler.cpp` constructed the filename from the parser directory and the supplied script name before passing it to `luaL_loadfile`. Execution is limited to already-installed valid Lua files; this is not arbitrary code execution, and the advisory states that file-write and upload paths require administrator privileges. This issue is addressed in version 2026.3.
Which versions are affected by CVE-2026-75520?
How do I fix CVE-2026-75520?
No fix has been published for CVE-2026-75520 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-75520 being exploited?
There is no known exploitation of CVE-2026-75520 in the wild and no public exploit code.
Sources
Also known as GHSA-8rv5-x8wv-c5c4.