{"id":"CVE-2026-118300","kind":"vulnerability","aliases":["CVE-2026-118300"],"related":[],"title":"Microsoft Excel: out-of-bounds read lets a remote attacker disclose information","description":"Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.","summary":"Microsoft Office Excel reads memory past the end of a buffer when processing crafted input. An unauthorized attacker over a network can use this to disclose information from the process.","severity":"medium","cvss":6.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"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":"2026-11-10T19:57:44+00:00","updated_at":"2026-11-10T19:57:44+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-11-10T19:57:44Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Excel: out-of-bounds read lets a remote attacker disclose information","impact":"low","summary":"Microsoft Office Excel reads memory past the end of a buffer when processing crafted input. An unauthorized attacker over a network can use this to disclose information from the process.","audience":"everyone","category":"package","nicknames":[],"who_cares":["microsoft-office","excel","windows"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"attacker reads some memory contents from Excel process","analyst_note":"Check the Microsoft Security Response Center entry for CVE-2026-118300 for affected Office builds, patch status and whether user action such as opening a file is required.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":[],"who_is_affected":"unknown","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000628,"input_tokens":4495,"output_tokens":356,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-118300':16A,19A '-2026':15A,18A 'allow':65C 'attack':11A,43B,68C 'bound':6A,59C 'buffer':36B 'craft':39B 'cve':14A,17A 'disclos':12A,51B,70C 'end':33B 'excel':2A,20B,28B,64C 'inform':13A,52B,71C 'input':40B 'let':8A 'memori':30B 'microsoft':1A,22B,26B,62C 'microsoft-offic':21B 'network':46B,74C 'offic':23B,27B,63C 'out-of-bound':3A,56C 'packag':24B 'past':31B 'process':38B,55B 'read':7A,29B,60C 'remot':10A 'unauthor':42B,67C 'use':48B 'window':25B","nicknames":[],"mitigations":[],"who_affected":null,"tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":null,"pkeys":[],"ptokens":[],"labels":["excel","medium","microsoftoffice","package","windows"],"campaign_type":null,"search_a":"'-118300':16A,19A '-2026':15A,18A 'attack':11A 'bound':6A 'cve':14A,17A 'disclos':12A 'excel':2A 'inform':13A 'let':8A 'microsoft':1A 'out-of-bound':3A 'read':7A 'remot':10A","search_b":"'attack':43B 'buffer':36B 'craft':39B 'disclos':51B 'end':33B 'excel':20B,28B 'inform':52B 'input':40B 'memori':30B 'microsoft':22B,26B 'microsoft-offic':21B 'network':46B 'offic':23B,27B 'packag':24B 'past':31B 'process':38B,55B 'read':29B 'unauthor':42B 'use':48B 'window':25B","search_c":"'allow':65C 'attack':68C 'bound':59C 'disclos':70C 'excel':64C 'inform':71C 'microsoft':62C 'network':74C 'offic':63C 'out-of-bound':56C 'read':60C 'unauthor':67C","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:N/A:N","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-118300","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118300","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"}