{"id":"CVE-2026-124179","kind":"vulnerability","aliases":["CVE-2026-124179"],"related":[],"title":"Microsoft Excel: out-of-bounds read can leak data over a network","description":"Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.","summary":"A memory read past the end of a buffer in Microsoft Excel lets an unauthorized attacker disclose information over a network. The sources give no detail on what data is exposed or how the file is delivered.","severity":"medium","cvss":6.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["excel","microsoft-office","other","windows"],"not_affected_if":[],"how_to_check":"- Check the installed Excel build against Microsoft's update history for CVE-2026-124179","fix":null,"status":"open","published_at":"2026-11-10T19:20:46+00:00","first_seen_at":"2026-11-10T19:25:13+00:00","triaged_at":"2026-11-10T19:56:16+00:00","updated_at":"2026-11-10T19:56:16+00:00","category":"other","confidence":0.4,"triage":{"at":"2026-11-10T19:56:16Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: out-of-bounds read can leak data over a network","impact":"low","summary":"A memory read past the end of a buffer in Microsoft Excel lets an unauthorized attacker disclose information over a network. The sources give no detail on what data is exposed or how the file is delivered.","audience":"businesses","category":"other","nicknames":[],"who_cares":["excel","microsoft-office","windows"],"confidence":0.4,"fix_status":"unknown","needs_auth":"unknown","worst_case":"Memory contents are disclosed to an attacker over the network.","analyst_note":"Find Microsoft's security update guide entry for CVE-2026-124179 to confirm affected builds, fixed versions, and whether user interaction is needed.","how_to_check":"- Check the installed Excel build against Microsoft's update history for CVE-2026-124179\n- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Organizations running Microsoft Office Excel. The sources do not say which Excel builds are affected, what triggers the read, or whether opening a file is required. unknown","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000672,"input_tokens":4495,"output_tokens":445,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-124179':16A,19A '-2026':15A,18A 'allow':72C 'attack':41B,75C 'bound':6A,66C 'buffer':34B 'cve':14A,17A 'data':10A,54B 'deliv':62B 'detail':51B 'disclos':42B,77C 'end':31B 'excel':2A,20B,37B,71C 'expos':56B 'file':60B 'give':49B 'inform':43B,78C 'leak':9A 'let':38B 'memori':27B 'microsoft':1A,22B,36B,69C 'microsoft-offic':21B 'network':13A,46B,81C 'offic':23B,70C 'out-of-bound':3A,63C 'past':29B 'read':7A,28B,67C 'sourc':48B 'unauthor':40B,74C 'window':25B","nicknames":[],"mitigations":[],"who_affected":"Organizations running Microsoft Office Excel. The sources do not say which Excel builds are affected, what triggers the read, or whether opening a file is required. unknown","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["excel","medium","microsoftoffice","other","windows"],"campaign_type":null,"search_a":"'-124179':16A,19A '-2026':15A,18A 'bound':6A 'cve':14A,17A 'data':10A 'excel':2A 'leak':9A 'microsoft':1A 'network':13A 'out-of-bound':3A 'read':7A","search_b":"'attack':41B 'buffer':34B 'data':54B 'deliv':62B 'detail':51B 'disclos':42B 'end':31B 'excel':20B,37B 'expos':56B 'file':60B 'give':49B 'inform':43B 'let':38B 'memori':27B 'microsoft':22B,36B 'microsoft-offic':21B 'network':46B 'offic':23B 'past':29B 'read':28B 'sourc':48B 'unauthor':40B 'window':25B","search_c":"'allow':72C 'attack':75C 'bound':66C 'disclos':77C 'excel':71C 'inform':78C 'microsoft':69C 'network':81C 'offic':70C 'out-of-bound':63C 'read':67C 'unauthor':74C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:20:46+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-124179","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124179","severity":null,"published_at":"2026-11-10T19:20:46+00:00","modified_at":"2026-11-10T19:20:47+00:00","first_seen_at":"2026-11-10T19:25:13+00:00","fetched_at":"2026-11-10T19:25:13+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"}