{"id":"CVE-2026-124178","kind":"vulnerability","aliases":["CVE-2026-124178"],"related":[],"title":"Microsoft Excel: out-of-bounds read lets a network attacker leak information","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 Office Excel lets an unauthorized attacker on the network disclose information. The sources give no further detail on what data can be read.","severity":"medium","cvss":6.5,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Microsoft Office Excel","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["excel","microsoft-office","other","windows"],"not_affected_if":[],"how_to_check":null,"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":"2026-11-10T19:56:17+00:00","updated_at":"2026-11-10T19:56:17+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T19:56:17Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: out-of-bounds read lets a network attacker leak information","impact":"low","summary":"A memory read past the end of a buffer in Microsoft Office Excel lets an unauthorized attacker on the network disclose information. The sources give no further detail on what data can be read.","audience":"businesses","category":"other","nicknames":[],"who_cares":["excel","microsoft-office","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"Attacker reads sensitive memory contents over the network","analyst_note":"Check the Microsoft Security Response Center entry for CVE-2026-124178 for affected versions, patch and any user interaction requirement.","how_to_check":"- unknown","plain_action":"","product_name":"Microsoft Office Excel","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Organizations running Microsoft Office Excel are exposed to this flaw. The sources do not say which Excel versions are affected or what triggers it, so the exact exposure is unknown.","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000668,"input_tokens":4495,"output_tokens":437,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-124178':16A,19A '-2026':15A,18A 'allow':72C 'attack':11A,45B,75C 'bound':6A,66C 'buffer':37B 'cve':14A,17A 'data':59B 'detail':56B 'disclos':49B,77C 'end':34B 'excel':2A,22A,23B,41B,71C 'give':53B 'inform':13A,50B,78C 'leak':12A 'let':8A,42B 'memori':30B 'microsoft':1A,20A,25B,39B,69C 'microsoft-offic':24B 'network':10A,48B,81C 'offic':26B,40B,70C 'office':21A 'out-of-bound':3A,63C 'past':32B 'read':7A,31B,62B,67C 'sourc':52B 'unauthor':44B,74C 'window':28B","nicknames":[],"mitigations":[],"who_affected":"Organizations running Microsoft Office Excel are exposed to this flaw. The sources do not say which Excel versions are affected or what triggers it, so the exact exposure is unknown.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":["microsoftofficeexcel","officeexcel"],"ptokens":["excel","microsoft","office"],"labels":["excel","medium","microsoftoffice","other","vendor","windows"],"campaign_type":null,"search_a":"'-124178':16A,19A '-2026':15A,18A 'attack':11A 'bound':6A 'cve':14A,17A 'excel':2A,22A 'inform':13A 'leak':12A 'let':8A 'microsoft':1A,20A 'network':10A 'office':21A 'out-of-bound':3A 'read':7A","search_b":"'attack':45B 'buffer':37B 'data':59B 'detail':56B 'disclos':49B 'end':34B 'excel':23B,41B 'give':53B 'inform':50B 'let':42B 'memori':30B 'microsoft':25B,39B 'microsoft-offic':24B 'network':48B 'offic':26B,40B 'past':32B 'read':31B,62B 'sourc':52B 'unauthor':44B 'window':28B","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-2026-124178","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124178","severity":null,"published_at":"2026-11-10T19:20:46+00:00","modified_at":"2026-11-10T19:20:46+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"}