{"id":"CVE-2026-109496","kind":"vulnerability","aliases":["CVE-2026-109496"],"related":[],"title":"Microsoft Visio: heap buffer overflow lets a network attacker run code","description":"Heap-based buffer overflow in Microsoft Office Visio allows an unauthorized attacker to execute code over a network.","summary":"A heap-based buffer overflow in Microsoft Office Visio lets an unauthorized attacker run code on a machine across a network. The sources give no further detail on the trigger or the affected Visio versions.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["microsoft-office","other","visio","windows"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:18:18+00:00","first_seen_at":"2026-11-10T19:24:25+00:00","triaged_at":"2026-11-10T19:33:56+00:00","updated_at":"2026-11-10T19:33:56+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T19:33:56Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Visio: heap buffer overflow lets a network attacker run code","impact":"high","summary":"A heap-based buffer overflow in Microsoft Office Visio lets an unauthorized attacker run code on a machine across a network. The sources give no further detail on the trigger or the affected Visio versions.","audience":"everyone","category":"other","nicknames":[],"who_cares":["visio","microsoft-office","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"Attacker runs arbitrary code on the affected computer over the network","analyst_note":"Find the Microsoft Security Response Center advisory for CVE-2026-109496 to get affected Visio versions, the fixed build, and whether user interaction (opening a file) is required.","how_to_check":"- unknown","plain_action":"unknown","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Anyone running Microsoft Office Visio is potentially exposed; the sources do not list affected versions or the triggering file or network path. unknown","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000662,"input_tokens":4496,"output_tokens":424,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find the Microsoft Security Response Center advisory for CVE-2026-109496 to get affected Visio versions, the fixed build, and whether user interaction (opening a file) is required.","search":"'-109496':14A,17A '-2026':13A,16A 'across':43B 'affect':57B 'allow':69C 'attack':9A,37B,72C 'base':27B,62C 'buffer':4A,28B,63C 'code':11A,39B,75C 'cve':12A,15A 'detail':51B 'execut':74C 'give':48B 'heap':3A,26B,61C 'heap-bas':25B,60C 'let':6A,34B 'machin':42B 'microsoft':1A,19B,31B,66C 'microsoft-offic':18B 'network':8A,45B,78C 'offic':20B,32B,67C 'overflow':5A,29B,64C 'run':10A,38B 'sourc':47B 'trigger':54B 'unauthor':36B,71C 'version':59B 'visio':2A,22B,33B,58B,68C 'window':23B","nicknames":[],"mitigations":[],"who_affected":"Anyone running Microsoft Office Visio is potentially exposed; the sources do not list affected versions or the triggering file or network path. unknown","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","microsoftoffice","other","visio","windows"],"campaign_type":null,"search_a":"'-109496':14A,17A '-2026':13A,16A 'attack':9A 'buffer':4A 'code':11A 'cve':12A,15A 'heap':3A 'let':6A 'microsoft':1A 'network':8A 'overflow':5A 'run':10A 'visio':2A","search_b":"'across':43B 'affect':57B 'attack':37B 'base':27B 'buffer':28B 'code':39B 'detail':51B 'give':48B 'heap':26B 'heap-bas':25B 'let':34B 'machin':42B 'microsoft':19B,31B 'microsoft-offic':18B 'network':45B 'offic':20B,32B 'overflow':29B 'run':38B 'sourc':47B 'trigger':54B 'unauthor':36B 'version':59B 'visio':22B,33B,58B 'window':23B","search_c":"'allow':69C 'attack':72C 'base':62C 'buffer':63C 'code':75C 'execut':74C 'heap':61C 'heap-bas':60C 'microsoft':66C 'network':78C 'offic':67C 'overflow':64C 'unauthor':71C 'visio':68C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:18:18+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-109496","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109496","severity":null,"published_at":"2026-11-10T19:18:18+00:00","modified_at":"2026-11-10T19:18:18+00:00","first_seen_at":"2026-11-10T19:24:25+00:00","fetched_at":"2026-11-10T19:24:25+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"}