{"id":"CVE-2026-118729","kind":"vulnerability","aliases":["CVE-2026-118729"],"related":[],"title":"Microsoft Excel: memory reuse flaw 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 over a network. Sources rate it high (CVSS 8.8) and do not say it is exploited in the wild.","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":"2026-11-10T19:19:49+00:00","first_seen_at":"2026-11-10T19:24:54+00:00","triaged_at":"2026-11-10T19:28:14+00:00","updated_at":"2026-11-10T19:28:14+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T19:28:14Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: memory reuse flaw lets a network attacker run code","impact":"high","summary":"A use-after-free bug in Microsoft Office Excel lets an unauthorized attacker run code over a network. Sources rate it high (CVSS 8.8) and do not say it is exploited in the wild.","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 on the victim's machine over the network","analyst_note":"Check the Microsoft Security Response Center entry for CVE-2026-118729 for affected versions, fixed builds, and whether a user must open a file.","how_to_check":"unknown","plain_action":"Update Microsoft Excel through Microsoft Update once Microsoft publishes a fix for this issue.","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Organizations and people running Microsoft Office Excel. The sources do not name affected versions or say which file or network path triggers the bug. unknown","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000668,"input_tokens":4482,"output_tokens":440,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Response Center entry for CVE-2026-118729 for affected versions, fixed builds, and whether a user must open a file.","search":"'-118729':14A,17A '-2026':13A,16A '8.8':48B 'allow':66C 'attack':9A,37B,69C 'bug':29B 'code':11A,39B,72C 'cve':12A,15A 'cvss':47B 'excel':2A,18B,33B,65C 'execut':71C 'exploit':55B 'flaw':5A 'free':28B,61C 'high':46B 'let':6A,34B 'memori':3A 'microsoft':1A,20B,31B,63C 'microsoft-offic':19B 'network':8A,42B,75C 'offic':21B,32B,64C 'rate':44B 'reus':4A 'run':10A,38B 'say':52B 'sourc':43B 'unauthor':36B,68C 'use':26B,59C 'use-after-fre':25B 'wild':58B 'window':23B","nicknames":[],"mitigations":[],"who_affected":"Organizations and people running Microsoft Office Excel. The sources do not name affected versions or say which file or network path triggers the bug. unknown","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 issue.","pkeys":[],"ptokens":[],"labels":["excel","high","microsoftoffice","other","windows"],"campaign_type":null,"search_a":"'-118729':14A,17A '-2026':13A,16A 'attack':9A 'code':11A 'cve':12A,15A 'excel':2A 'flaw':5A 'let':6A 'memori':3A 'microsoft':1A 'network':8A 'reus':4A 'run':10A","search_b":"'8.8':48B 'attack':37B 'bug':29B 'code':39B 'cvss':47B 'excel':18B,33B 'exploit':55B 'free':28B 'high':46B 'let':34B 'microsoft':20B,31B 'microsoft-offic':19B 'network':42B 'offic':21B,32B 'rate':44B 'run':38B 'say':52B 'sourc':43B 'unauthor':36B 'use':26B 'use-after-fre':25B 'wild':58B 'window':23B","search_c":"'allow':66C 'attack':69C 'code':72C 'excel':65C 'execut':71C 'free':61C 'microsoft':63C 'network':75C 'offic':64C 'unauthor':68C 'use':59C","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-2026-118729","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118729","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"}