{"id":"CVE-2026-118296","kind":"vulnerability","aliases":["CVE-2026-118296"],"related":[],"title":"Microsoft Excel: double free lets a network attacker run code","description":"Double free in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.","summary":"A double free bug in Microsoft Office Excel lets an unauthorized attacker run code over a network. The sources give no further detail on how a file or message triggers it.","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":"2026-11-10T19:19:43+00:00","first_seen_at":"2026-11-10T19:24:52+00:00","triaged_at":"2026-11-10T19:29:55+00:00","updated_at":"2026-11-10T19:29:55+00:00","category":"package","confidence":0.4,"triage":{"at":"2026-11-10T19:29:54Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: double free lets a network attacker run code","impact":"high","summary":"A double free bug in Microsoft Office Excel lets an unauthorized attacker run code over a network. The sources give no further detail on how a file or message triggers it.","audience":"everyone","category":"package","nicknames":[],"who_cares":["excel","microsoft-office","windows"],"confidence":0.4,"fix_status":"unknown","needs_auth":"no","worst_case":"attacker runs code on the machine opening Excel","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-118296 for affected Office builds, patch and whether user interaction (opening a file) is required.","how_to_check":"- unknown","plain_action":"unknown","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":0.000637,"input_tokens":4480,"output_tokens":378,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-118296 for affected Office builds, patch and whether user interaction (opening a file) is required.","search":"'-118296':13A,16A '-2026':12A,15A 'allow':62C 'attack':8A,37B,65C 'bug':29B 'code':10A,39B,68C 'cve':11A,14A 'detail':48B 'doubl':3A,27B,56C 'excel':2A,19A,20B,33B,61C 'execut':67C 'file':52B 'free':4A,28B,57C 'give':45B 'let':5A,34B 'messag':54B 'microsoft':1A,17A,22B,31B,59C 'microsoft-offic':21B 'network':7A,42B,71C 'offic':23B,32B,60C 'office':18A 'packag':24B 'run':9A,38B 'sourc':44B 'trigger':55B 'unauthor':36B,64C 'window':25B","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":null,"pkeys":["microsoftofficeexcel","officeexcel"],"ptokens":["excel","microsoft","office"],"labels":["excel","high","microsoftoffice","package","vendor","windows"],"campaign_type":null,"search_a":"'-118296':13A,16A '-2026':12A,15A 'attack':8A 'code':10A 'cve':11A,14A 'doubl':3A 'excel':2A,19A 'free':4A 'let':5A 'microsoft':1A,17A 'network':7A 'office':18A 'run':9A","search_b":"'attack':37B 'bug':29B 'code':39B 'detail':48B 'doubl':27B 'excel':20B,33B 'file':52B 'free':28B 'give':45B 'let':34B 'messag':54B 'microsoft':22B,31B 'microsoft-offic':21B 'network':42B 'offic':23B,32B 'packag':24B 'run':38B 'sourc':44B 'trigger':55B 'unauthor':36B 'window':25B","search_c":"'allow':62C 'attack':65C 'code':68C 'doubl':56C 'excel':61C 'execut':67C 'free':57C 'microsoft':59C 'network':71C 'offic':60C 'unauthor':64C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:43+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-2026-118296","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118296","severity":null,"published_at":"2026-11-10T19:19:43+00:00","modified_at":"2026-11-10T19:19:43+00:00","first_seen_at":"2026-11-10T19:24:52+00:00","fetched_at":"2026-11-10T19:24:52+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"}