{"id":"CVE-2026-124174","kind":"vulnerability","aliases":["CVE-2026-124174"],"related":[],"title":"Microsoft Excel: heap buffer overflow lets an attacker run code over network","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 Office Excel lets an unauthorized attacker run code over a network. The sources give no further detail on the trigger or the affected versions.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Microsoft Office Excel","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["excel","microsoft-office","other"],"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":"2026-11-10T19:26:16+00:00","updated_at":"2026-11-10T19:26:16+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T19:26:16Z","model":"claude-haiku-5-5","output":{"fix":"- unknown","reach":"network","title":"Microsoft Excel: heap buffer overflow lets an attacker run code over network","impact":"high","summary":"A heap-based buffer overflow in Microsoft Office Excel lets an unauthorized attacker run code over a network. The sources give no further detail on the trigger or the affected versions.","audience":"everyone","category":"other","nicknames":[],"who_cares":["excel","microsoft-office"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"attacker runs code on the machine over the network","analyst_note":"Check the Microsoft Security Update Guide for CVE-2026-124174 for affected Office builds, the fixed build, and whether a file must be opened (user interaction).","how_to_check":"- unknown","plain_action":"","product_name":"Microsoft Office Excel","needs_analyst":true,"not_affected_if":[],"who_is_affected":"unknown","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000643,"input_tokens":4496,"output_tokens":387,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Update Guide for CVE-2026-124174 for affected Office builds, the fixed build, and whether a file must be opened (user interaction).","search":"'-124174':15A,18A '-2026':14A,17A 'affect':56B 'allow':67C 'attack':8A,39B,70C 'base':29B,60C 'buffer':4A,30B,61C 'code':10A,41B,73C 'cve':13A,16A 'detail':50B 'excel':2A,21A,22B,35B,66C 'execut':72C 'give':47B 'heap':3A,28B,59C 'heap-bas':27B,58C 'let':6A,36B 'microsoft':1A,19A,24B,33B,64C 'microsoft-offic':23B 'network':12A,44B,76C 'offic':25B,34B,65C 'office':20A 'overflow':5A,31B,62C 'run':9A,40B 'sourc':46B 'trigger':53B 'unauthor':38B,69C 'version':57B","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":null,"pkeys":["microsoftofficeexcel","officeexcel"],"ptokens":["excel","microsoft","office"],"labels":["excel","high","microsoftoffice","other","vendor"],"campaign_type":null,"search_a":"'-124174':15A,18A '-2026':14A,17A 'attack':8A 'buffer':4A 'code':10A 'cve':13A,16A 'excel':2A,21A 'heap':3A 'let':6A 'microsoft':1A,19A 'network':12A 'office':20A 'overflow':5A 'run':9A","search_b":"'affect':56B 'attack':39B 'base':29B 'buffer':30B 'code':41B 'detail':50B 'excel':22B,35B 'give':47B 'heap':28B 'heap-bas':27B 'let':36B 'microsoft':24B,33B 'microsoft-offic':23B 'network':44B 'offic':25B,34B 'overflow':31B 'run':40B 'sourc':46B 'trigger':53B 'unauthor':38B 'version':57B","search_c":"'allow':67C 'attack':70C 'base':60C 'buffer':61C 'code':73C 'excel':66C 'execut':72C 'heap':59C 'heap-bas':58C 'microsoft':64C 'network':76C 'offic':65C 'overflow':62C 'unauthor':69C","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: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-2026-124174","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124174","severity":null,"published_at":"2026-11-10T19:20:44+00:00","modified_at":"2026-11-10T19:20:45+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"}