{"id":"CVE-2026-49341","kind":"vulnerability","aliases":["CVE-2026-49341"],"related":[],"title":"BACnet Stack: remote denial of service in default demo server","description":"BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to version 1.5.1, there is a remotely reachable denial-of-service vulnerability in bacnet-stack affecting the default demo server built from the unmodified apps/server/main.c. This issue has been patched in version 1.5.1.","summary":"BACnet Stack is an open source C library implementing the BACnet building-automation protocol for embedded systems. Before version 1.5.1, a remote attacker can crash the default demo server built from the unmodified apps/server/main.c, causing denial of service.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["bacnet-stack","building-automation","embedded","package"],"not_affected_if":["modified-server","version-1.5.1-or-later"],"how_to_check":"- Check the bacnet-stack version in use; `1.5.1` or later is not affected\n- Look for builds of apps/server/main.c that were not modified from the upstream demo server","fix":"- bacnet-stack: move to `1.5.1` or later","status":"open","published_at":"2026-11-13T16:19:01+00:00","first_seen_at":"2026-11-13T16:47:34+00:00","triaged_at":"2026-11-13T16:48:40+00:00","updated_at":"2026-11-13T16:48:40+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-13T16:48:40Z","model":"claude-haiku-5-5","output":{"fix":"- bacnet-stack: move to `1.5.1` or later","reach":"network","title":"BACnet Stack: remote denial of service in default demo server","impact":"low","summary":"BACnet Stack is an open source C library implementing the BACnet building-automation protocol for embedded systems. Before version 1.5.1, a remote attacker can crash the default demo server built from the unmodified apps/server/main.c, causing denial of service.","audience":"developers","category":"package","nicknames":[],"who_cares":["bacnet-stack","embedded","building-automation"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"remote attacker crashes the demo server, denying service","analyst_note":"","how_to_check":"- Check the bacnet-stack version in use; `1.5.1` or later is not affected\n- Look for builds of apps/server/main.c that were not modified from the upstream demo server","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["version-1.5.1-or-later","modified-server"],"who_is_affected":"Teams that build the default BACnet demo server from apps/server/main.c without modification and run it on a reachable network. Systems that use a modified server or a version at or after 1.5.1 are not affected.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000699,"input_tokens":4567,"output_tokens":484,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-49341':13A,16A '1.5.1':45B,81C,113C 'affect':96C 'apps/server/main.c':59B,105C 'attack':48B 'autom':22B,38B 'bacnet':1A,18B,25B,35B,64C,68C,94C 'bacnet-stack':17B,93C 'build':21B,37B 'building-autom':20B,36B 'built':55B,101C 'c':31B,73C 'caus':60B 'crash':50B 'cve':11A,14A 'default':8A,52B,98C 'demo':9A,53B,99C 'denial':4A,61B,88C 'denial-of-servic':87C 'embed':23B,41B,76C 'implement':33B 'issu':107C 'librari':32B,74C 'open':29B,69C 'packag':24B 'patch':110C 'prior':78C 'protocol':39B,71C 'reachabl':86C 'remot':3A,47B,85C 'server':10A,54B,100C 'servic':6A,63B,90C 'sourc':30B,70C 'stack':2A,19B,26B,65C,72C,95C 'system':42B,77C 'unmodifi':58B,104C 'version':44B,80C,112C 'vulner':91C","nicknames":[],"mitigations":[],"who_affected":"Teams that build the default BACnet demo server from apps/server/main.c without modification and run it on a reachable network. Systems that use a modified server or a version at or after 1.5.1 are not affected.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["bacnetstack","buildingautomation","embedded","high","package"],"campaign_type":null,"search_a":"'-2026':12A,15A '-49341':13A,16A 'bacnet':1A 'cve':11A,14A 'default':8A 'demo':9A 'denial':4A 'remot':3A 'server':10A 'servic':6A 'stack':2A","search_b":"'1.5.1':45B 'apps/server/main.c':59B 'attack':48B 'autom':22B,38B 'bacnet':18B,25B,35B 'bacnet-stack':17B 'build':21B,37B 'building-autom':20B,36B 'built':55B 'c':31B 'caus':60B 'crash':50B 'default':52B 'demo':53B 'denial':61B 'embed':23B,41B 'implement':33B 'librari':32B 'open':29B 'packag':24B 'protocol':39B 'remot':47B 'server':54B 'servic':63B 'sourc':30B 'stack':19B,26B 'system':42B 'unmodifi':58B 'version':44B","search_c":"'1.5.1':81C,113C 'affect':96C 'apps/server/main.c':105C 'bacnet':64C,68C,94C 'bacnet-stack':93C 'built':101C 'c':73C 'default':98C 'demo':99C 'denial':88C 'denial-of-servic':87C 'embed':76C 'issu':107C 'librari':74C 'open':69C 'patch':110C 'prior':78C 'protocol':71C 'reachabl':86C 'remot':85C 'server':100C 'servic':90C 'sourc':70C 'stack':65C,72C,95C 'system':77C 'unmodifi':104C 'version':80C,112C 'vulner':91C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-07-05T02:01:49+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-49341","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49341","severity":null,"published_at":"2026-11-13T16:19:01+00:00","modified_at":"2026-11-13T16:19:01+00:00","first_seen_at":"2026-11-13T16:47:34+00:00","fetched_at":"2026-11-13T16:47:34+00:00","note":null}],"documents":[{"id":147665,"url":"https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-7r8r-2rj2-5wvr","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-07-05T02:01:49+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"}