{"id":"CVE-2026-66281","kind":"vulnerability","aliases":["CVE-2026-66281"],"related":[],"title":"EmberZNet: malformed Discover Attributes command causes infinite loop on device","description":"In EmberZNet 9.1.1 and earlier, a malformed Discover Attributes command can result in a loop with unreachable exit condition (infinite loop). These messages must come from a device that has already joined the network. Only devices supporting manufacturer-specific clusters are impacted.","summary":"A malformed Discover Attributes command in EmberZNet 9.1.1 and earlier puts the device into a loop with no reachable exit, which hangs it. Only devices that support manufacturer-specific clusters are impacted, and the message has to come from a device already joined to the network.","severity":"medium","cvss":6.0,"epss":0.00219,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["embedded","emberznet","infrastructure","iot","zigbee"],"not_affected_if":["no-manufacturer-specific-clusters","no-untrusted-joined-devices"],"how_to_check":"- Check the EmberZNet SDK version in the project (unknown exact command from sources)\n- Confirm whether the device firmware uses manufacturer-specific clusters (unknown from sources)","fix":"- Move to a fixed EmberZNet release newer than `9.1.1` (fixed version unknown from sources)","status":"open","published_at":"2026-10-22T14:17:43+00:00","first_seen_at":"2026-10-23T21:57:31+00:00","triaged_at":"2026-10-25T04:05:27+00:00","updated_at":"2026-10-25T04:05:27+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-25T04:05:27Z","model":"claude-haiku-5-5","output":{"fix":"- Move to a fixed EmberZNet release newer than `9.1.1` (fixed version unknown from sources)","reach":"network","title":"EmberZNet: malformed Discover Attributes command causes infinite loop on device","impact":"low","summary":"A malformed Discover Attributes command in EmberZNet 9.1.1 and earlier puts the device into a loop with no reachable exit, which hangs it. Only devices that support manufacturer-specific clusters are impacted, and the message has to come from a device already joined to the network.","category":"infrastructure","nicknames":[],"who_cares":["zigbee","emberznet","iot","embedded"],"confidence":0.6,"needs_auth":"yes","worst_case":"A device hangs in an infinite loop and stops responding to the network","analyst_note":"Find the fixed EmberZNet version and vendor advisory via the NVD entry at https://nvd.nist.gov/vuln/detail/CVE-2026-66281.","how_to_check":"- Check the EmberZNet SDK version in the project (unknown exact command from sources)\n- Confirm whether the device firmware uses manufacturer-specific clusters (unknown from sources)","needs_analyst":true,"not_affected_if":["no-manufacturer-specific-clusters","no-untrusted-joined-devices"],"who_is_affected":"Zigbee devices built on EmberZNet 9.1.1 and earlier that support manufacturer-specific clusters are affected. The attacker must already be a device joined to the Zigbee network, so networks with no untrusted joined devices are at lower risk. Devices without manufacturer-specific clusters are not impacted.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000637,"input_tokens":3357,"output_tokens":603,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-66281':13A,16A '9.1.1':29B,71C 'alreadi':64B,99C 'attribut':4A,25B,77C 'caus':6A 'cluster':52B,109C 'come':60B,93C 'command':5A,26B,78C 'condit':87C 'cve':11A,14A 'devic':10A,34B,46B,63B,96C,104C 'discov':3A,24B,76C 'earlier':31B,73C 'embed':17B 'emberznet':1A,18B,28B,70C 'exit':41B,86C 'hang':43B 'impact':54B,111C 'infinit':7A,88C 'infrastructur':19B 'iot':20B 'join':65B,100C 'loop':8A,37B,83C,89C 'malform':2A,23B,75C 'manufactur':50B,107C 'manufacturer-specif':49B,106C 'messag':57B,91C 'must':92C 'network':68B,102C 'put':32B 'reachabl':40B 'result':80C 'specif':51B,108C 'support':48B,105C 'unreach':85C 'zigbe':21B","nicknames":[],"mitigations":[],"who_affected":"Zigbee devices built on EmberZNet 9.1.1 and earlier that support manufacturer-specific clusters are affected. The attacker must already be a device joined to the Zigbee network, so networks with no untrusted joined devices are at lower risk. Devices without manufacturer-specific clusters are not impacted.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-22T14:17:43+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"product-security@silabs.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-66281","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66281","severity":null,"published_at":"2026-10-22T14:17:43+00:00","modified_at":"2026-10-23T12:18:15+00:00","first_seen_at":"2026-10-23T21:57:31+00:00","fetched_at":"2026-10-23T22:29:02+00:00","note":null},{"source":"epss","external_id":"CVE-2026-66281","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-66281","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-24T07:15:51+00:00","fetched_at":"2026-10-24T07:15:51+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}