{"id":"CVE-2026-118715","kind":"vulnerability","aliases":["CVE-2026-118715"],"related":[],"title":"Microsoft Excel: heap buffer overflow lets an attacker gain higher privileges","description":"Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to elevate privileges over a network.","summary":"A heap-based buffer overflow in Microsoft Office Excel lets an unauthorized attacker raise their privileges over a network. The sources give no further detail on the trigger or the exact scope of access gained.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["excel","microsoft-office","other","windows"],"not_affected_if":[],"how_to_check":"- Check the installed Microsoft Excel build in Excel under File > Account (unknown otherwise)\n- Compare the Office build against Microsoft's security update guide entry for CVE-2026-118715 (unknown otherwise)","fix":null,"status":"open","published_at":"2026-11-10T19:19:47+00:00","first_seen_at":"2026-11-10T19:24:53+00:00","triaged_at":"2026-11-10T19:28:29+00:00","updated_at":"2026-11-10T19:28:29+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T19:28:29Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: heap buffer overflow lets an attacker gain higher privileges","impact":"high","summary":"A heap-based buffer overflow in Microsoft Office Excel lets an unauthorized attacker raise their privileges over a network. The sources give no further detail on the trigger or the exact scope of access gained.","audience":"businesses","category":"other","nicknames":[],"who_cares":["microsoft-office","excel","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"unknown","worst_case":"Attacker gains elevated privileges on the affected machine over the network.","analyst_note":"Find the Microsoft security update guide entry for CVE-2026-118715 to get affected builds, fixed versions and whether a user must open a file.","how_to_check":"- Check the installed Microsoft Excel build in Excel under File > Account (unknown otherwise)\n- Compare the Office build against Microsoft's security update guide entry for CVE-2026-118715 (unknown otherwise)","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Organisations running Microsoft Office Excel are exposed; the sources do not state the affected versions or which configurations are at risk. unknown whether a default install is affected.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000698,"input_tokens":4502,"output_tokens":495,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find the Microsoft security update guide entry for CVE-2026-118715 to get affected builds, fixed versions and whether a user must open a file.","search":"'-118715':14A,17A '-2026':13A,16A 'access':58B 'allow':69C 'attack':8A,37B,72C 'base':27B,62C 'buffer':4A,28B,63C 'cve':12A,15A 'detail':49B 'elev':74C 'exact':55B 'excel':2A,18B,33B,68C 'gain':9A,59B 'give':46B 'heap':3A,26B,61C 'heap-bas':25B,60C 'higher':10A 'let':6A,34B 'microsoft':1A,20B,31B,66C 'microsoft-offic':19B 'network':43B,78C 'offic':21B,32B,67C 'overflow':5A,29B,64C 'privileg':11A,40B,75C 'rais':38B 'scope':56B 'sourc':45B 'trigger':52B 'unauthor':36B,71C 'window':23B","nicknames":[],"mitigations":[],"who_affected":"Organisations running Microsoft Office Excel are exposed; the sources do not state the affected versions or which configurations are at risk. unknown whether a default install is affected.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["excel","high","microsoftoffice","other","windows"],"campaign_type":null,"search_a":"'-118715':14A,17A '-2026':13A,16A 'attack':8A 'buffer':4A 'cve':12A,15A 'excel':2A 'gain':9A 'heap':3A 'higher':10A 'let':6A 'microsoft':1A 'overflow':5A 'privileg':11A","search_b":"'access':58B 'attack':37B 'base':27B 'buffer':28B 'detail':49B 'exact':55B 'excel':18B,33B 'gain':59B 'give':46B 'heap':26B 'heap-bas':25B 'let':34B 'microsoft':20B,31B 'microsoft-offic':19B 'network':43B 'offic':21B,32B 'overflow':29B 'privileg':40B 'rais':38B 'scope':56B 'sourc':45B 'trigger':52B 'unauthor':36B 'window':23B","search_c":"'allow':69C 'attack':72C 'base':62C 'buffer':63C 'elev':74C 'excel':68C 'heap':61C 'heap-bas':60C 'microsoft':66C 'network':78C 'offic':67C 'overflow':64C 'privileg':75C 'unauthor':71C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:47+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-2026-118715","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118715","severity":null,"published_at":"2026-11-10T19:19:47+00:00","modified_at":"2026-11-10T19:19:47+00:00","first_seen_at":"2026-11-10T19:24:53+00:00","fetched_at":"2026-11-10T19:24:53+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"}