{"id":"CVE-2026-75520","state":"PUBLISHED","title":"Domoticz: Missing authorization and path traversal in the udevices Lua parser handler","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.","publishedAt":"2026-10-28T22:30:59.693Z","updatedAt":"2026-10-28T22:30:59.693Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["domoticz domoticz"],"affected":[{"vendor":"domoticz","product":"domoticz","versions":[{"version":"<= 2026.2","status":"affected"}]}],"references":["https://github.com/domoticz/domoticz/security/advisories/GHSA-8rv5-x8wv-c5c4","https://github.com/domoticz/domoticz/commit/73ed0495af6de3309f27cfc0091e803300ab5ccd","https://github.com/domoticz/domoticz/blob/2026.3/main/WebServerCmds.cpp#L3445-L3451","https://github.com/domoticz/domoticz/releases/tag/2026.3","https://github.com/domoticz/libwebem/blob/dfe946fa32f4c211662e47ef55b8cedfc50a6a76/include/libwebem/session.h#L10-L17"],"weaknesses":["CWE-22","CWE-862"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/75xxx/CVE-2026-75520.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-75520","state":"PUBLISHED","datePublished":"2026-10-28T22:30:59.693Z","dateUpdated":"2026-10-28T22:30:59.693Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-17T20:49:21.599Z"},"containers":{"cna":{"title":"Domoticz: Missing authorization and path traversal in the udevices Lua parser handler","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"domoticz","product":"domoticz","versions":[{"version":"<= 2026.2","status":"affected"}]}],"references":[{"url":"https://github.com/domoticz/domoticz/security/advisories/GHSA-8rv5-x8wv-c5c4","name":"https://github.com/domoticz/domoticz/security/advisories/GHSA-8rv5-x8wv-c5c4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/domoticz/domoticz/commit/73ed0495af6de3309f27cfc0091e803300ab5ccd","name":"https://github.com/domoticz/domoticz/commit/73ed0495af6de3309f27cfc0091e803300ab5ccd","tags":["x_refsource_MISC"]},{"url":"https://github.com/domoticz/domoticz/blob/2026.3/main/WebServerCmds.cpp#L3445-L3451","name":"https://github.com/domoticz/domoticz/blob/2026.3/main/WebServerCmds.cpp#L3445-L3451","tags":["x_refsource_MISC"]},{"url":"https://github.com/domoticz/domoticz/releases/tag/2026.3","name":"https://github.com/domoticz/domoticz/releases/tag/2026.3","tags":["x_refsource_MISC"]},{"url":"https://github.com/domoticz/libwebem/blob/dfe946fa32f4c211662e47ef55b8cedfc50a6a76/include/libwebem/session.h#L10-L17","name":"https://github.com/domoticz/libwebem/blob/dfe946fa32f4c211662e47ef55b8cedfc50a6a76/include/libwebem/session.h#L10-L17","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-862","lang":"en","description":"CWE-862: Missing Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-28T22:30:59.693Z"},"source":{"advisory":"GHSA-8rv5-x8wv-c5c4","discovery":"UNKNOWN"}}}}}