{"id":"CVE-2026-124170","kind":"vulnerability","aliases":["CVE-2026-124170"],"related":[],"title":"Microsoft Excel: heap buffer overflow lets a remote attacker run code","description":"Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.","summary":"A heap-based buffer overflow in Microsoft Excel lets an unauthorized attacker run code over a network. The sources give no further detail on the trigger or affected versions.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["microsoft-excel","microsoft-office","vendor","windows"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:20:44+00:00","first_seen_at":"2026-11-10T19:25:13+00:00","triaged_at":"2026-11-10T19:43:12+00:00","updated_at":"2026-11-10T19:43:12+00:00","category":"vendor","confidence":0.5,"triage":{"at":"2026-11-10T19:43:12Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: heap buffer overflow lets a remote attacker run code","impact":"high","summary":"A heap-based buffer overflow in Microsoft Excel lets an unauthorized attacker run code over a network. The sources give no further detail on the trigger or affected versions.","audience":"businesses","category":"vendor","nicknames":[],"who_cares":["microsoft-excel","microsoft-office","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"Attacker runs code on the affected machine over the network","analyst_note":"Check the Microsoft Security Response Center advisory for CVE-2026-124170 for affected Excel builds, fixed versions and whether user interaction is needed.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Organizations running Microsoft Excel are the ones exposed; the sources do not say which versions or which file or network path triggers the flaw. unknown","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000654,"input_tokens":4496,"output_tokens":408,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Response Center advisory for CVE-2026-124170 for affected Excel builds, fixed versions and whether user interaction is needed.","search":"'-124170':14A,17A '-2026':13A,16A 'affect':54B 'allow':65C 'attack':9A,38B,68C 'base':29B,58C 'buffer':4A,30B,59C 'code':11A,40B,71C 'cve':12A,15A 'detail':49B 'excel':2A,20B,34B,64C 'execut':70C 'give':46B 'heap':3A,28B,57C 'heap-bas':27B,56C 'let':6A,35B 'microsoft':1A,19B,22B,33B,62C 'microsoft-excel':18B 'microsoft-offic':21B 'network':43B,74C 'offic':23B,63C 'overflow':5A,31B,60C 'remot':8A 'run':10A,39B 'sourc':45B 'trigger':52B 'unauthor':37B,67C 'vendor':24B 'version':55B 'window':25B","nicknames":[],"mitigations":[],"who_affected":"Organizations running Microsoft Excel are the ones exposed; the sources do not say which versions or which file or network path triggers the flaw. unknown","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","microsoftexcel","microsoftoffice","vendor","windows"],"campaign_type":null,"search_a":"'-124170':14A,17A '-2026':13A,16A 'attack':9A 'buffer':4A 'code':11A 'cve':12A,15A 'excel':2A 'heap':3A 'let':6A 'microsoft':1A 'overflow':5A 'remot':8A 'run':10A","search_b":"'affect':54B 'attack':38B 'base':29B 'buffer':30B 'code':40B 'detail':49B 'excel':20B,34B 'give':46B 'heap':28B 'heap-bas':27B 'let':35B 'microsoft':19B,22B,33B 'microsoft-excel':18B 'microsoft-offic':21B 'network':43B 'offic':23B 'overflow':31B 'run':39B 'sourc':45B 'trigger':52B 'unauthor':37B 'vendor':24B 'version':55B 'window':25B","search_c":"'allow':65C 'attack':68C 'base':58C 'buffer':59C 'code':71C 'excel':64C 'execut':70C 'heap':57C 'heap-bas':56C 'microsoft':62C 'network':74C 'offic':63C 'overflow':60C 'unauthor':67C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:20:44+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/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-2026-124170","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124170","severity":null,"published_at":"2026-11-10T19:20:44+00:00","modified_at":"2026-11-10T19:20:44+00:00","first_seen_at":"2026-11-10T19:25:13+00:00","fetched_at":"2026-11-10T19:25:13+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"}