{"id":"CVE-2026-62973","kind":"vulnerability","aliases":["CVE-2026-62973"],"related":[],"title":"BACnet Stack: malicious device reply causes out-of-bounds read in readpropm","description":"BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.5, 1.5.1, and 1.6.0, a remote out-of-bounds read exists in the official BACnet client application apps/readpropm in bacnet-stack commit e2bdbf6. When readpropm sends a legitimate ReadPropertyMultiple request to a malicious BACnet/IP peer, the peer can reply with a malformed but structurally valid ReadPropertyMultiple-ACK that drives the client into a global-buffer-overflow read on the global receive buffer Rx_Buf. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0.","summary":"BACnet Stack is a C library for the BACnet building-automation protocol, and its readpropm client can be made to read past a global receive buffer. A malicious BACnet/IP peer that answers a ReadPropertyMultiple request with a malformed but structurally valid reply can trigger the over-read.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"bacnet-stack","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["bacnet-stack","building-automation","c","embedded","package"],"not_affected_if":["no-readpropm-built","trusted-network-only"],"how_to_check":"- Check the BACnet Stack version in use against the fixed versions listed below.\n- Look for the `apps/readpropm` client built from the bacnet-stack source in your tree or firmware.","fix":"- Move to `1.4.5`, `1.5.1`, or `1.6.0` (fixed versions per the advisory, matching each release line).","status":"open","published_at":"2026-11-13T16:19:28+00:00","first_seen_at":"2026-11-13T16:47:35+00:00","triaged_at":"2026-11-13T16:48:32+00:00","updated_at":"2026-11-13T16:48:32+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-13T16:48:32Z","model":"claude-haiku-5-5","output":{"fix":"- Move to `1.4.5`, `1.5.1`, or `1.6.0` (fixed versions per the advisory, matching each release line).","reach":"network","title":"BACnet Stack: malicious device reply causes out-of-bounds read in readpropm","impact":"medium","summary":"BACnet Stack is a C library for the BACnet building-automation protocol, and its readpropm client can be made to read past a global receive buffer. A malicious BACnet/IP peer that answers a ReadPropertyMultiple request with a malformed but structurally valid reply can trigger the over-read.","audience":"developers","category":"package","nicknames":[],"who_cares":["bacnet-stack","embedded","building-automation","c"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Client reads out of bounds on its global receive buffer, possibly crashing.","analyst_note":"Confirm the affected package and whether the out-of-bounds read leaks data or only crashes; check the vendor advisory linked from the source.","how_to_check":"- Check the BACnet Stack version in use against the fixed versions listed below.\n- Look for the `apps/readpropm` client built from the bacnet-stack source in your tree or firmware.\n- unknown whether other components of the library are affected.","plain_action":"","product_name":"bacnet-stack","needs_analyst":true,"not_affected_if":["no-readpropm-built","trusted-network-only"],"who_is_affected":"Only builds that include the readpropm BACnet client application are described as affected, and the peer must be a BACnet/IP device that the client sends a ReadPropertyMultiple request to. Systems that only use the library as a server, or that never run readpropm against untrusted networks, face a smaller exposure. Teams that embed the library in building-automation or embedded devices should check which builds ship readpropm.","user_interaction":"no","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000813,"input_tokens":4698,"output_tokens":686,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':15A,18A '-62973':16A,19A '1.4.5':98C,173C '1.5.1':99C,174C '1.6.0':101C,176C 'ack':147C 'answer':64B 'applic':115C 'apps/readpropm':116C 'autom':28B,43B 'bacnet':1A,21A,24B,32B,40B,81C,85C,113C,119C 'bacnet-stack':20A,23B,118C 'bacnet/ip':61B,133C 'bound':10A,107C 'buf':165C 'buffer':58B,156C,163C 'build':27B,42B 'building-autom':26B,41B 'c':29B,36B,90C 'caus':6A 'client':48B,114C,151C 'commit':121C 'cve':14A,17A 'devic':4A 'drive':149C 'e2bdbf6':122C 'embed':30B,93C 'exist':109C 'global':56B,155C,161C 'global-buffer-overflow':154C 'issu':167C 'legitim':127C 'librari':37B,91C 'made':51B 'malform':70B,141C 'malici':3A,60B,132C 'offici':112C 'open':86C 'out-of-bound':7A,104C 'over-read':78B 'overflow':157C 'packag':31B 'past':54B 'patch':170C 'peer':62B,134C,136C 'prior':95C 'protocol':44B,88C 'read':11A,53B,80B,108C,158C 'readpropertymultipl':66B,128C,146C 'readpropertymultiple-ack':145C 'readpropm':13A,47B,124C 'receiv':57B,162C 'remot':103C 'repli':5A,74B,138C 'request':67B,129C 'rx':164C 'send':125C 'sourc':87C 'stack':2A,22A,25B,33B,82C,89C,120C 'structur':72B,143C 'system':94C 'trigger':76B 'valid':73B,144C 'version':97C,172C","nicknames":[],"mitigations":[],"who_affected":"Only builds that include the readpropm BACnet client application are described as affected, and the peer must be a BACnet/IP device that the client sends a ReadPropertyMultiple request to. Systems that only use the library as a server, or that never run readpropm against untrusted networks, face a smaller exposure. Teams that embed the library in building-automation or embedded devices should check which builds ship readpropm.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":["bacnetstack"],"ptokens":["bacnet","stack"],"labels":["bacnetstack","buildingautomation","c","embedded","high","package","vendor"],"campaign_type":null,"search_a":"'-2026':15A,18A '-62973':16A,19A 'bacnet':1A,21A 'bacnet-stack':20A 'bound':10A 'caus':6A 'cve':14A,17A 'devic':4A 'malici':3A 'out-of-bound':7A 'read':11A 'readpropm':13A 'repli':5A 'stack':2A,22A","search_b":"'answer':64B 'autom':28B,43B 'bacnet':24B,32B,40B 'bacnet-stack':23B 'bacnet/ip':61B 'buffer':58B 'build':27B,42B 'building-autom':26B,41B 'c':29B,36B 'client':48B 'embed':30B 'global':56B 'librari':37B 'made':51B 'malform':70B 'malici':60B 'over-read':78B 'packag':31B 'past':54B 'peer':62B 'protocol':44B 'read':53B,80B 'readpropertymultipl':66B 'readpropm':47B 'receiv':57B 'repli':74B 'request':67B 'stack':25B,33B 'structur':72B 'trigger':76B 'valid':73B","search_c":"'1.4.5':98C,173C '1.5.1':99C,174C '1.6.0':101C,176C 'ack':147C 'applic':115C 'apps/readpropm':116C 'bacnet':81C,85C,113C,119C 'bacnet-stack':118C 'bacnet/ip':133C 'bound':107C 'buf':165C 'buffer':156C,163C 'c':90C 'client':114C,151C 'commit':121C 'drive':149C 'e2bdbf6':122C 'embed':93C 'exist':109C 'global':155C,161C 'global-buffer-overflow':154C 'issu':167C 'legitim':127C 'librari':91C 'malform':141C 'malici':132C 'offici':112C 'open':86C 'out-of-bound':104C 'overflow':157C 'patch':170C 'peer':134C,136C 'prior':95C 'protocol':88C 'read':108C,158C 'readpropertymultipl':128C,146C 'readpropertymultiple-ack':145C 'readpropm':124C 'receiv':162C 'remot':103C 'repli':138C 'request':129C 'rx':164C 'send':125C 'sourc':87C 'stack':82C,89C,120C 'structur':143C 'system':94C 'valid':144C 'version':97C,172C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-07-16T13:17:22+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-2026-62973","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-62973","severity":null,"published_at":"2026-11-13T16:19:28+00:00","modified_at":"2026-11-13T16:19:28+00:00","first_seen_at":"2026-11-13T16:47:35+00:00","fetched_at":"2026-11-13T16:47:35+00:00","note":null}],"documents":[{"id":147674,"url":"https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-3xxw-jfwm-rq9c","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-07-16T13:17:22+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"}