{"id":"CVE-2026-64675","kind":"vulnerability","aliases":["CVE-2026-64675"],"related":[],"title":"BACnet Stack: unauthenticated UDP packet triggers out-of-bounds read","description":"BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.5 and 1.5.1, a single unauthenticated BACnet/IP UDP datagram (port 47808) triggers an out-of-bounds read in xy_color_decode() (src/bacnet/lighting.c), reachable pre-authentication through two default-registered service handlers: the UnconfirmedRequest WriteGroup service (0x0A) and Confirmed WriteProperty on a BACnetXYColor-typed property. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0.","summary":"BACnet Stack is an open source BACnet protocol C library used in embedded building-automation devices. A single unauthenticated BACnet/IP UDP packet on port 47808 can trigger an out-of-bounds read in the lighting color decoder, which can crash or leak memory.","severity":"medium","cvss":5.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["bacnet","building-automation","c","embedded","package"],"not_affected_if":["no-bacnet-ip","port-47808-filtered"],"how_to_check":"- Check the BACnet Stack version in the firmware or build: unknown whether a command is given by the sources.\n- Look for BACnet/IP devices or builds using the library on UDP port `47808` reachable from untrusted networks.","fix":"- Upgrade to `1.4.5`, `1.5.1`, or `1.6.0` (the patched versions for their release lines).","status":"open","published_at":"2026-11-13T19:19:33+00:00","first_seen_at":"2026-11-13T19:52:09+00:00","triaged_at":"2026-11-13T19:54:16+00:00","updated_at":"2026-11-13T19:54:16+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-13T19:54:16Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade to `1.4.5`, `1.5.1`, or `1.6.0` (the patched versions for their release lines).","reach":"network","title":"BACnet Stack: unauthenticated UDP packet triggers out-of-bounds read","impact":"medium","summary":"BACnet Stack is an open source BACnet protocol C library used in embedded building-automation devices. A single unauthenticated BACnet/IP UDP packet on port 47808 can trigger an out-of-bounds read in the lighting color decoder, which can crash or leak memory.","audience":"developers","category":"package","nicknames":[],"who_cares":["bacnet","embedded","building-automation","c"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"out-of-bounds memory read crashes the device","analyst_note":"","how_to_check":"- Check the BACnet Stack version in the firmware or build: unknown whether a command is given by the sources.\n- Look for BACnet/IP devices or builds using the library on UDP port `47808` reachable from untrusted networks.","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["no-bacnet-ip","port-47808-filtered"],"who_is_affected":"Products that embed the BACnet Stack C library and expose BACnet/IP on UDP port 47808 with the lighting WriteGroup or WriteProperty services registered by default. Systems that do not run BACnet/IP or keep the port off untrusted networks are less exposed. unknown whether the sources list more detail.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000752,"input_tokens":4674,"output_tokens":569,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-64675':14A,17A '0x0a':125C '1.4.5':87C,142C '1.5.1':89C,143C '1.6.0':145C '47808':50B,97C 'authent':113C 'autom':21B,40B 'bacnet':1A,18B,25B,31B,70C,74C 'bacnet/ip':45B,93C 'bacnetxycolor':132C 'bacnetxycolor-typ':131C 'bound':10A,57B,103C 'build':20B,39B 'building-autom':19B,38B 'c':22B,33B,79C 'color':62B,107C 'confirm':127C 'crash':66B 'cve':12A,15A 'datagram':95C 'decod':63B,108C 'default':117C 'default-regist':116C 'devic':41B 'embed':23B,37B,82C 'handler':120C 'issu':136C 'leak':68B 'librari':34B,80C 'light':61B 'memori':69B 'open':29B,75C 'out-of-bound':7A,54B,100C 'packag':24B 'packet':5A,47B 'patch':139C 'port':49B,96C 'pre':112C 'pre-authent':111C 'prior':84C 'properti':134C 'protocol':32B,77C 'reachabl':110C 'read':11A,58B,104C 'regist':118C 'servic':119C,124C 'singl':43B,91C 'sourc':30B,76C 'src/bacnet/lighting.c':109C 'stack':2A,26B,71C,78C 'system':83C 'trigger':6A,52B,98C 'two':115C 'type':133C 'udp':4A,46B,94C 'unauthent':3A,44B,92C 'unconfirmedrequest':122C 'use':35B 'version':86C,141C 'writegroup':123C 'writeproperti':128C 'xy':106C","nicknames":[],"mitigations":[],"who_affected":"Products that embed the BACnet Stack C library and expose BACnet/IP on UDP port 47808 with the lighting WriteGroup or WriteProperty services registered by default. Systems that do not run BACnet/IP or keep the port off untrusted networks are less exposed. unknown whether the sources list more detail.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["bacnet","buildingautomation","c","embedded","medium","package"],"campaign_type":null,"search_a":"'-2026':13A,16A '-64675':14A,17A 'bacnet':1A 'bound':10A 'cve':12A,15A 'out-of-bound':7A 'packet':5A 'read':11A 'stack':2A 'trigger':6A 'udp':4A 'unauthent':3A","search_b":"'47808':50B 'autom':21B,40B 'bacnet':18B,25B,31B 'bacnet/ip':45B 'bound':57B 'build':20B,39B 'building-autom':19B,38B 'c':22B,33B 'color':62B 'crash':66B 'decod':63B 'devic':41B 'embed':23B,37B 'leak':68B 'librari':34B 'light':61B 'memori':69B 'open':29B 'out-of-bound':54B 'packag':24B 'packet':47B 'port':49B 'protocol':32B 'read':58B 'singl':43B 'sourc':30B 'stack':26B 'trigger':52B 'udp':46B 'unauthent':44B 'use':35B","search_c":"'0x0a':125C '1.4.5':87C,142C '1.5.1':89C,143C '1.6.0':145C '47808':97C 'authent':113C 'bacnet':70C,74C 'bacnet/ip':93C 'bacnetxycolor':132C 'bacnetxycolor-typ':131C 'bound':103C 'c':79C 'color':107C 'confirm':127C 'datagram':95C 'decod':108C 'default':117C 'default-regist':116C 'embed':82C 'handler':120C 'issu':136C 'librari':80C 'open':75C 'out-of-bound':100C 'patch':139C 'port':96C 'pre':112C 'pre-authent':111C 'prior':84C 'properti':134C 'protocol':77C 'reachabl':110C 'read':104C 'regist':118C 'servic':119C,124C 'singl':91C 'sourc':76C 'src/bacnet/lighting.c':109C 'stack':71C,78C 'system':83C 'trigger':98C 'two':115C 'type':133C 'udp':94C 'unauthent':92C 'unconfirmedrequest':122C 'version':86C,141C 'writegroup':123C 'writeproperti':128C 'xy':106C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-07-05T02:04:56+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-64675","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64675","severity":null,"published_at":"2026-11-13T19:19:33+00:00","modified_at":"2026-11-13T19:19:33+00:00","first_seen_at":"2026-11-13T19:52:09+00:00","fetched_at":"2026-11-13T19:52:09+00:00","note":null}],"documents":[{"id":149167,"url":"https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-mmg6-p4pr-cj6h","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-07-05T02:04:56+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}