CVE-2025-1221: DoS in Zigbee device due to heavy traffic

Severity: medium (CVSS 5.9 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-30 · updated 2026-06-17
Weakness: CWE-667

Description

A Zigbee Radio Co-Processor (RCP), which is using SiLabs EmberZNet Zigbee stack, was unable to send messages to the host system (CPCd) due to heavy Zigbee traffic, resulting in a Denial of Service (DoS) attack, Only hard reset will bring the device to normal operation

Affected products

silabs.com Zigbee: through 4.3.3; through 2024.6.1; 4.4.3

References

https://community.silabs.com/068Vm00000Sadyn
https://www.silabs.com/documents/public/release-notes/emberznet-release-notes-7.4.4.0.pdf
https://www.silabs.com/documents/public/release-notes/emberznet-release-notes-8.0.2.0.pdf
https://www.silabs.com/documents/public/release-notes/emberznet-release-notes-8.1.0.0.pdf

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