{"id":"CVE-2026-118712","kind":"vulnerability","aliases":["CVE-2026-118712"],"related":[],"title":"Microsoft Excel: integer underflow lets an unauthorized attacker run code","description":"Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.","summary":"Microsoft Office Excel contains an integer underflow flaw that can wrap a value around. A remote unauthenticated attacker can exploit it to execute code.","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":null,"fix":null,"status":"open","published_at":"2026-11-10T19:19:46+00:00","first_seen_at":"2026-11-10T19:24:53+00:00","triaged_at":"2026-11-10T19:28:26+00:00","updated_at":"2026-11-10T19:28:26+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T19:28:26Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: integer underflow lets an unauthorized attacker run code","impact":"high","summary":"Microsoft Office Excel contains an integer underflow flaw that can wrap a value around. A remote unauthenticated attacker can exploit it to execute code.","audience":"everyone","category":"other","nicknames":[],"who_cares":["microsoft-office","excel","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"attacker runs code over the network","analyst_note":"Check the Microsoft Security Response Center advisory for CVE-2026-118712 for affected Office builds, patched versions and whether opening a file is required.","how_to_check":"unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"unknown","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000621,"input_tokens":4504,"output_tokens":342,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Response Center advisory for CVE-2026-118712 for affected Office builds, patched versions and whether opening a file is required.","search":"'-118712':13A,16A '-2026':12A,15A 'allow':56C 'around':36B 'attack':8A,40B,59C 'code':10A,46B,62C 'contain':26B 'cve':11A,14A 'excel':2A,17B,25B,55C 'execut':45B,61C 'exploit':42B 'flaw':30B 'integ':3A,28B,47C 'let':5A 'microsoft':1A,19B,23B,53C 'microsoft-offic':18B 'network':65C 'offic':20B,24B,54C 'remot':38B 'run':9A 'unauthent':39B 'unauthor':7A,58C 'underflow':4A,29B,48C 'valu':35B 'window':22B 'wrap':33B,49C 'wraparound':51C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":null,"pkeys":[],"ptokens":[],"labels":["excel","high","microsoftoffice","other","windows"],"campaign_type":null,"search_a":"'-118712':13A,16A '-2026':12A,15A 'attack':8A 'code':10A 'cve':11A,14A 'excel':2A 'integ':3A 'let':5A 'microsoft':1A 'run':9A 'unauthor':7A 'underflow':4A","search_b":"'around':36B 'attack':40B 'code':46B 'contain':26B 'excel':17B,25B 'execut':45B 'exploit':42B 'flaw':30B 'integ':28B 'microsoft':19B,23B 'microsoft-offic':18B 'offic':20B,24B 'remot':38B 'unauthent':39B 'underflow':29B 'valu':35B 'window':22B 'wrap':33B","search_c":"'allow':56C 'attack':59C 'code':62C 'excel':55C 'execut':61C 'integ':47C 'microsoft':53C 'network':65C 'offic':54C 'unauthor':58C 'underflow':48C 'wrap':49C 'wraparound':51C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:46+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-2026-118712","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118712","severity":null,"published_at":"2026-11-10T19:19:46+00:00","modified_at":"2026-11-10T19:19:46+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"}