CVE-2026-19061: medium-severity vulnerability in InstaKNXServiceApp

A flaw has been found in Insta InstaKNXServiceApp 1.2.3.1469. Affected by this issue is the function CreateWebClientAndDownloadFileList of the component Firmware Update Handler. Executing a manipulation can lead to insufficient verification of data authenticity. It is possible to launch the attack remotely. Attacks of this nature are highly complex. The exploitation is known to be difficult. There are still doubts about whether this vulnerability truly exists. The vendor explains: "[T]he entry suggests that the device does not verify the authenticity of the update. This is incorrect. The device performs an authenticity check after the complete update has been transferred. If this check fails, the update is not installed and the previously installed firmware continues to run".