{"id":"CVE-2026-109459","kind":"vulnerability","aliases":["CVE-2026-109459"],"related":[],"title":"Windows Message Queuing: heap overflow lets an unauthorized attacker run code","description":"Heap-based buffer overflow in Windows Message Queuing Queue Manager allows an unauthorized attacker to execute code over a network.","summary":"A heap-based buffer overflow in the Windows Message Queuing Queue Manager lets an attacker write past allocated memory. The flaw can be triggered over the network and allows code execution without authentication.","severity":"high","cvss":8.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","msmq","windows"],"not_affected_if":["msmq-not-installed"],"how_to_check":"- Check whether the Message Queuing (MSMQ) Windows feature is installed and running on the host","fix":null,"status":"open","published_at":"2026-11-10T19:18:14+00:00","first_seen_at":"2026-11-10T19:24:24+00:00","triaged_at":"2026-11-10T19:35:59+00:00","updated_at":"2026-11-10T19:35:59+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-10T19:35:59Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Windows Message Queuing: heap overflow lets an unauthorized attacker run code","impact":"high","summary":"A heap-based buffer overflow in the Windows Message Queuing Queue Manager lets an attacker write past allocated memory. The flaw can be triggered over the network and allows code execution without authentication.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","msmq"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"unauthenticated remote attacker runs code on the Windows host","analyst_note":"Confirm affected Windows builds, whether MSMQ is on by default, and the Microsoft fix or patch from the MSRC advisory for CVE-2026-109459.","how_to_check":"- Check whether the Message Queuing (MSMQ) Windows feature is installed and running on the host\n- unknown for exact affected Windows builds, the sources do not list them","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["msmq-not-installed"],"who_is_affected":"Windows servers and workstations with the Message Queuing feature installed and its Queue Manager reachable from the network are the exposed systems. The sources do not say which Windows builds are affected or whether the feature is on by default, so teams should confirm that before deciding whether they can skip it.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000709,"input_tokens":4504,"output_tokens":517,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Confirm affected Windows builds, whether MSMQ is on by default, and the Microsoft fix or patch from the MSRC advisory for CVE-2026-109459.","search":"'-109459':14A,17A '-2026':13A,16A 'alloc':39B 'allow':50B,66C 'attack':9A,36B,69C 'authent':54B 'base':24B,57C 'buffer':25B,58C 'code':11A,51B,72C 'cve':12A,15A 'execut':52B,71C 'flaw':42B 'heap':4A,23B,56C 'heap-bas':22B,55C 'infrastructur':18B 'let':6A,34B 'manag':33B,65C 'memori':40B 'messag':2A,30B,62C 'msmq':19B 'network':48B,75C 'overflow':5A,26B,59C 'past':38B 'queu':3A,31B,63C 'queue':32B,64C 'run':10A 'trigger':45B 'unauthor':8A,68C 'window':1A,20B,29B,61C 'without':53B 'write':37B","nicknames":[],"mitigations":[],"who_affected":"Windows servers and workstations with the Message Queuing feature installed and its Queue Manager reachable from the network are the exposed systems. The sources do not say which Windows builds are affected or whether the feature is on by default, so teams should confirm that before deciding whether they can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","infrastructure","msmq","windows"],"campaign_type":null,"search_a":"'-109459':14A,17A '-2026':13A,16A 'attack':9A 'code':11A 'cve':12A,15A 'heap':4A 'let':6A 'messag':2A 'overflow':5A 'queu':3A 'run':10A 'unauthor':8A 'window':1A","search_b":"'alloc':39B 'allow':50B 'attack':36B 'authent':54B 'base':24B 'buffer':25B 'code':51B 'execut':52B 'flaw':42B 'heap':23B 'heap-bas':22B 'infrastructur':18B 'let':34B 'manag':33B 'memori':40B 'messag':30B 'msmq':19B 'network':48B 'overflow':26B 'past':38B 'queu':31B 'queue':32B 'trigger':45B 'window':20B,29B 'without':53B 'write':37B","search_c":"'allow':66C 'attack':69C 'base':57C 'buffer':58C 'code':72C 'execut':71C 'heap':56C 'heap-bas':55C 'manag':65C 'messag':62C 'network':75C 'overflow':59C 'queu':63C 'queue':64C 'unauthor':68C 'window':61C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:18:14+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-109459","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109459","severity":null,"published_at":"2026-11-10T19:18:14+00:00","modified_at":"2026-11-10T19:18:15+00:00","first_seen_at":"2026-11-10T19:24:24+00:00","fetched_at":"2026-11-10T19:24:24+00:00","note":null}],"documents":[],"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"}