{"id":"CVE-2026-118730","kind":"vulnerability","aliases":["CVE-2026-118730"],"related":[],"title":"Microsoft Excel: use-after-free lets a network attacker run code","description":"Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.","summary":"A use-after-free bug in Microsoft Office Excel lets an unauthorized attacker run code on a machine over the network. The sources give no affected versions, no fix and no exploitation data.","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","package","windows"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:19:49+00:00","first_seen_at":"2026-11-10T19:24:54+00:00","triaged_at":"2026-11-10T19:28:12+00:00","updated_at":"2026-11-10T19:28:12+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-11-10T19:28:12Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: use-after-free lets a network attacker run code","impact":"high","summary":"A use-after-free bug in Microsoft Office Excel lets an unauthorized attacker run code on a machine over the network. The sources give no affected versions, no fix and no exploitation data.","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 machine over the network","analyst_note":"Check the Microsoft Security Response Center advisory for this CVE for affected builds, the fixed update and whether user interaction (opening a file) is needed.","how_to_check":"- unknown","plain_action":"Update Microsoft Excel through Microsoft Update once Microsoft publishes a fix for this flaw.","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":0.000657,"input_tokens":4482,"output_tokens":417,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Response Center advisory for this CVE for affected builds, the fixed update and whether user interaction (opening a file) is needed.","search":"'-118730':15A,18A '-2026':14A,17A 'affect':54B 'allow':69C 'attack':10A,41B,72C 'bug':33B 'code':12A,43B,75C 'cve':13A,16A 'data':61B 'excel':2A,21A,22B,37B,68C 'execut':74C 'exploit':60B 'fix':57B 'free':6A,32B,64C 'give':52B 'let':7A,38B 'machin':46B 'microsoft':1A,19A,24B,35B,66C 'microsoft-offic':23B 'network':9A,49B,78C 'offic':25B,36B,67C 'office':20A 'packag':26B 'run':11A,42B 'sourc':51B 'unauthor':40B,71C 'use':4A,30B,62C 'use-after-fre':3A,29B 'version':55B 'window':27B","nicknames":[],"mitigations":[],"who_affected":null,"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 for this flaw.","pkeys":["microsoftofficeexcel","officeexcel"],"ptokens":["excel","microsoft","office"],"labels":["excel","high","microsoftoffice","package","vendor","windows"],"campaign_type":null,"search_a":"'-118730':15A,18A '-2026':14A,17A 'attack':10A 'code':12A 'cve':13A,16A 'excel':2A,21A 'free':6A 'let':7A 'microsoft':1A,19A 'network':9A 'office':20A 'run':11A 'use':4A 'use-after-fre':3A","search_b":"'affect':54B 'attack':41B 'bug':33B 'code':43B 'data':61B 'excel':22B,37B 'exploit':60B 'fix':57B 'free':32B 'give':52B 'let':38B 'machin':46B 'microsoft':24B,35B 'microsoft-offic':23B 'network':49B 'offic':25B,36B 'packag':26B 'run':42B 'sourc':51B 'unauthor':40B 'use':30B 'use-after-fre':29B 'version':55B 'window':27B","search_c":"'allow':69C 'attack':72C 'code':75C 'excel':68C 'execut':74C 'free':64C 'microsoft':66C 'network':78C 'offic':67C 'unauthor':71C 'use':62C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:49+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-2026-118730","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118730","severity":null,"published_at":"2026-11-10T19:19:49+00:00","modified_at":"2026-11-10T19:19:49+00:00","first_seen_at":"2026-11-10T19:24:54+00:00","fetched_at":"2026-11-10T19:24:54+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"}