{"id":"CVE-2026-120791","kind":"vulnerability","aliases":["CVE-2026-120791"],"related":[],"title":"Microsoft Excel: heap 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 on a machine over a network. The sources give a CVSS score of 8.8 and do not say which Excel versions are affected or how the file or network path is triggered.","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","windows"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:20:28+00:00","first_seen_at":"2026-11-10T19:25:08+00:00","triaged_at":"2026-11-10T19:27:50+00:00","updated_at":"2026-11-10T19:27:50+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T19:27:50Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: heap 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 on a machine over a network. The sources give a CVSS score of 8.8 and do not say which Excel versions are affected or how the file or network path is triggered.","audience":"everyone","category":"other","nicknames":[],"who_cares":["microsoft-office","excel","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"unknown","worst_case":"Attacker runs code on the machine over the network","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-120791 for affected builds, patched versions and whether user interaction is needed.","how_to_check":"- unknown","plain_action":"Update Microsoft Excel through Microsoft Update once Microsoft publishes a fix; the sources do not name a patched version.","product_name":"Microsoft Office Excel","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Organizations and people who run Microsoft Office Excel. The sources do not say which Excel builds or configurations are affected, or whether a crafted file or a network service is needed to trigger it.","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000703,"input_tokens":4496,"output_tokens":506,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-120791 for affected builds, patched versions and whether user interaction is needed.","search":"'-120791':14A,17A '-2026':13A,16A '8.8':56B 'affect':65B 'allow':84C 'attack':7A,40B,87C 'base':30B,77C 'buffer':31B,78C 'code':9A,42B,90C 'cve':12A,15A 'cvss':53B 'excel':2A,20A,21B,36B,62B,83C 'execut':89C 'file':69B 'give':51B 'heap':3A,29B,76C 'heap-bas':28B,75C 'let':5A,37B 'machin':45B 'microsoft':1A,18A,23B,34B,81C 'microsoft-offic':22B 'network':11A,48B,71B,93C 'offic':24B,35B,82C 'office':19A 'overflow':4A,32B,79C 'path':72B 'run':8A,41B 'say':60B 'score':54B 'sourc':50B 'trigger':74B 'unauthor':39B,86C 'version':63B 'window':26B","nicknames":[],"mitigations":[],"who_affected":"Organizations and people who run Microsoft Office Excel. The sources do not say which Excel builds or configurations are affected, or whether a crafted file or a network service is needed to trigger it.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":"Update Microsoft Excel through Microsoft Update once Microsoft publishes a fix; the sources do not name a patched version.","pkeys":["microsoftofficeexcel","officeexcel"],"ptokens":["excel","microsoft","office"],"labels":["excel","high","microsoftoffice","other","vendor","windows"],"campaign_type":null,"search_a":"'-120791':14A,17A '-2026':13A,16A 'attack':7A 'code':9A 'cve':12A,15A 'excel':2A,20A 'heap':3A 'let':5A 'microsoft':1A,18A 'network':11A 'office':19A 'overflow':4A 'run':8A","search_b":"'8.8':56B 'affect':65B 'attack':40B 'base':30B 'buffer':31B 'code':42B 'cvss':53B 'excel':21B,36B,62B 'file':69B 'give':51B 'heap':29B 'heap-bas':28B 'let':37B 'machin':45B 'microsoft':23B,34B 'microsoft-offic':22B 'network':48B,71B 'offic':24B,35B 'overflow':32B 'path':72B 'run':41B 'say':60B 'score':54B 'sourc':50B 'trigger':74B 'unauthor':39B 'version':63B 'window':26B","search_c":"'allow':84C 'attack':87C 'base':77C 'buffer':78C 'code':90C 'excel':83C 'execut':89C 'heap':76C 'heap-bas':75C 'microsoft':81C 'network':93C 'offic':82C 'overflow':79C 'unauthor':86C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:20:28+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-2026-120791","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-120791","severity":null,"published_at":"2026-11-10T19:20:28+00:00","modified_at":"2026-11-10T19:20:28+00:00","first_seen_at":"2026-11-10T19:25:08+00:00","fetched_at":"2026-11-10T19:25:08+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"}