CVE-2026-17610 in SiSDK
Summary
by MITRE • 08/28/2026
In SiSDK v2026.6.0 and earlier, high network traffic loads can cause a dropped ACK leading to a denial of service. This is only present for EFR32MG24 and EFR32MG26 devices running concurrent multiprotocol Zigbee and Thread.
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Analysis
by VulDB Data Team • 08/28/2026
The vulnerability identified in Silicon Labs SiSDK versions 2026.6.0 and earlier represents a significant reliability issue within the wireless connectivity stack, specifically affecting devices equipped with EFR32MG24 and EFR32MG26 radio chips when operating under concurrent multiprotocol conditions involving both Zigbee and Thread networks. This flaw manifests as a denial of service condition triggered by high network traffic loads, where the system fails to properly handle acknowledgment packets, leading to dropped ACKs that disrupt normal communication flows. The root cause lies in the resource contention or scheduling inefficiencies within the radio driver or protocol stack when managing simultaneous connections across two distinct wireless standards, which share underlying hardware resources such as the RF front-end and baseband processor.
From a technical perspective, this issue aligns with CWE-400, Uncontrolled Resource Consumption, where excessive network traffic exhausts available buffer space or processing time required to process incoming acknowledgment frames. When the device is subjected to heavy load from both Zigbee and Thread networks concurrently, the internal queue management mechanisms fail to prioritize or correctly schedule ACK transmissions. This results in critical acknowledgments being dropped rather than transmitted, causing the sender to assume packet loss and initiate retransmissions. These unnecessary retransmissions further exacerbate network congestion, creating a feedback loop that degrades performance until the connection effectively stalls or drops entirely.
The operational impact of this vulnerability is severe for deployments relying on stable mesh networking in smart home or industrial IoT environments. Since both Zigbee and Thread are designed to provide robust, self-healing mesh networks, the inability to maintain reliable acknowledgment traffic undermines the fundamental promise of these protocols. Devices may experience intermittent connectivity, increased latency, and eventual disconnection from their respective networks. For users running concurrent multiprotocol setups, this can lead to a complete loss of control over connected devices, requiring manual intervention or power cycling to restore service. The restriction to EFR32MG24 and MG26 chips indicates that the issue is tied to specific hardware revisions or firmware implementations unique to these silicon generations, potentially due to differences in their radio scheduling algorithms compared to other series like the MG12 or newer MG28 variants which may have different architectural approaches to multiprotocol handling.
In terms of threat modeling and industry standards, this vulnerability can be mapped to MITRE ATT&CK technique T1499, Endpoint Denial of Service, although it is triggered by legitimate high-traffic scenarios rather than malicious exploitation. However, an attacker could potentially weaponize this flaw by generating sustained high-volume traffic on either the Zigbee or Thread network to induce a denial of service against the entire multiprotocol device. This makes the vulnerability particularly dangerous in shared infrastructure environments where one compromised node can degrade the availability of neighboring nodes through induced congestion. The lack of proper flow control and ACK prioritization highlights a gap in defensive design principles related to resource management under stress conditions.
Mitigation strategies primarily involve updating the SiSDK firmware to versions later than 2026.6.0, where Silicon Labs has likely implemented fixes for the radio scheduling logic or improved buffer handling during multiprotocol operation. Until an update is available, network administrators should consider reducing traffic loads on affected devices by limiting message frequency or optimizing mesh topology to reduce hop counts and congestion points. Additionally, segregating Zigbee and Thread networks onto different physical channels where possible may help alleviate resource contention, although this depends on the specific radio capabilities of the EFR32 chips in use. Monitoring network logs for signs of excessive retransmissions can also serve as an early warning indicator that a device is approaching its processing limits under load.