CVE-2025-1221: silabs.com Zigbee · Improper Locking
Affects silabs.com ZigbeeSource CVE Database V5
Not known to be exploited · CVSS 5.9 Medium.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| silabs.com Zigbee | Affected
| Fixed in– |
AI-suggested
- Network Segmentation: Isolate Zigbee networks from general IT networks to limit adjacent network access and reduce the attack surface.
- Access Controls: Enforce strict access controls and authentication on devices and network segments hosting Zigbee RCPs to prevent unauthorized local access.
- Monitoring and Alerts: Implement monitoring for unusual traffic patterns or device unresponsiveness in Zigbee networks to detect potential exploitation attempts early.
- Firmware Updates: Regularly check for and apply vendor patches or firmware updates from Silicon Labs as they become available to address this vulnerability.
- Device Hardening: Where possible, configure devices to allow remote reboot or recovery mechanisms to minimize downtime caused by the need for hard resets.
- Traffic Throttling: Implement traffic shaping or rate limiting on Zigbee networks to prevent heavy traffic conditions that trigger the vulnerability.
- Vendor Engagement: Engage with Silicon Labs and device manufacturers to obtain timelines for patches and request mitigation guidance tailored to specific device models.
- Incident Response Planning: Prepare response procedures for potential DoS events affecting Zigbee devices, including rapid identification and recovery steps.
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
References
- silabs.com/documents/public/release-notes/emberznet-release-notes-7.4.4.0.pdf (opens in a new tab)
- silabs.com/documents/public/release-notes/emberznet-release-notes-8.0.2.0.pdf (opens in a new tab)
- silabs.com/documents/public/release-notes/emberznet-release-notes-8.1.0.0.pdf (opens in a new tab)
- community.silabs.com/068Vm00000Sadyn (opens in a new tab)