A malformed Discover Attributes command can trigger an infinite loop in the EmberZNet protocol stack, causing the affected device to consume CPU resources without progressing. Because the loop has no reachable exit condition, the device becomes unresponsive and may reboot, leading to loss of network connectivity until the fault is cleared. The flaw is a classic uncontrolled loop (CWE-835).

Silicon Labs EmberZNet versions 9.1.1 and earlier that include manufacturer‑specific cluster support are vulnerable. The vulnerability manifests only when a joined device sends the malformed command, so devices that do not support manufacturer‑specific clusters are not impacted.

The CVSS score of 6 indicates a moderate severity. EPSS data is not available, so the likelihood of exploitation cannot be quantified, and the vulnerability is not listed in the CISA KEV catalog. The attacker must be authenticated to the network and able to send a malformed Discover Attributes message from a device that has already joined the network, which implies that the vulnerability is APT‑grade or requires device compromise. Once triggered, the infinite loop will only affect the target device and not propagate to other nodes, but the loss of that node’s functionality can disrupt critical network operations.