{"id":"CVE-2026-118700","kind":"vulnerability","aliases":["CVE-2026-118700"],"related":[],"title":"Microsoft Excel: stack buffer overflow lets a remote attacker run code","description":"Stack-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.","summary":"A stack-based buffer overflow in Microsoft Excel lets an unauthorized attacker run code over a network. The sources give no fixed Office build and no detail on how a file or message reaches the flaw.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["excel","microsoft-office","package","windows"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:19:44+00:00","first_seen_at":"2026-11-10T19:24:52+00:00","triaged_at":"2026-11-10T19:29:51+00:00","updated_at":"2026-11-10T19:29:51+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-11-10T19:29:51Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: stack buffer overflow lets a remote attacker run code","impact":"high","summary":"A stack-based buffer overflow in Microsoft Excel lets an unauthorized attacker run code over a network. The sources give no fixed Office build and no detail on how a file or message reaches the flaw.","audience":"everyone","category":"package","nicknames":[],"who_cares":["microsoft-office","excel","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"Attacker runs code on the victim's machine over the network","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-118700 for affected builds, fixed versions, and whether a file open or preview triggers it.","how_to_check":"- unknown","plain_action":"Update Microsoft Excel through Microsoft's normal Office updates once a patch is listed for your version.","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Anyone who opens Excel documents or uses Excel on a machine where the flaw is present. The sources do not say which Excel builds, file types or preview paths are affected, so unknown.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000679,"input_tokens":4496,"output_tokens":459,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-118700 for affected builds, fixed versions, and whether a file open or preview triggers it.","search":"'-118700':14A,17A '-2026':13A,16A 'allow':70C 'attack':9A,36B,73C 'base':27B,63C 'buffer':4A,28B,64C 'build':48B 'code':11A,38B,76C 'cve':12A,15A 'detail':51B 'excel':2A,18B,32B,69C 'execut':75C 'file':55B 'fix':46B 'flaw':60B 'give':44B 'let':6A,33B 'messag':57B 'microsoft':1A,20B,31B,67C 'microsoft-offic':19B 'network':41B,79C 'offic':21B,47B,68C 'overflow':5A,29B,65C 'packag':22B 'reach':58B 'remot':8A 'run':10A,37B 'sourc':43B 'stack':3A,26B,62C 'stack-bas':25B,61C 'unauthor':35B,72C 'window':23B","nicknames":[],"mitigations":[],"who_affected":"Anyone who opens Excel documents or uses Excel on a machine where the flaw is present. The sources do not say which Excel builds, file types or preview paths are affected, so unknown.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":"Update Microsoft Excel through Microsoft's normal Office updates once a patch is listed for your version.","pkeys":[],"ptokens":[],"labels":["excel","high","microsoftoffice","package","windows"],"campaign_type":null,"search_a":"'-118700':14A,17A '-2026':13A,16A 'attack':9A 'buffer':4A 'code':11A 'cve':12A,15A 'excel':2A 'let':6A 'microsoft':1A 'overflow':5A 'remot':8A 'run':10A 'stack':3A","search_b":"'attack':36B 'base':27B 'buffer':28B 'build':48B 'code':38B 'detail':51B 'excel':18B,32B 'file':55B 'fix':46B 'flaw':60B 'give':44B 'let':33B 'messag':57B 'microsoft':20B,31B 'microsoft-offic':19B 'network':41B 'offic':21B,47B 'overflow':29B 'packag':22B 'reach':58B 'run':37B 'sourc':43B 'stack':26B 'stack-bas':25B 'unauthor':35B 'window':23B","search_c":"'allow':70C 'attack':73C 'base':63C 'buffer':64C 'code':76C 'excel':69C 'execut':75C 'microsoft':67C 'network':79C 'offic':68C 'overflow':65C 'stack':62C 'stack-bas':61C 'unauthor':72C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:44+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-2026-118700","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118700","severity":null,"published_at":"2026-11-10T19:19:44+00:00","modified_at":"2026-11-10T19:19:44+00:00","first_seen_at":"2026-11-10T19:24:52+00:00","fetched_at":"2026-11-10T19:24:52+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"}