{"id":"CVE-2026-66801","kind":"vulnerability","aliases":["CVE-2026-66801"],"related":[],"title":"Xbox: heap buffer overflow lets a network attacker run code","description":"Heap-based buffer overflow in Xbox allows an unauthorized attacker to execute code over a network.","summary":"A heap-based buffer overflow in Xbox lets an unauthorized attacker reach the device over a network. The sources say the attacker can execute code.","severity":"critical","cvss":9.8,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Xbox","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["console","network","other","rce","xbox"],"not_affected_if":[],"how_to_check":"Unknown until MSRC details are read. Check MSRC CVE-2026-66801 for affected Xbox models and the fixed system update; on the console see Settings > System > Updates and install any pending update.","fix":null,"status":"open","published_at":"2026-11-10T19:21:17+00:00","first_seen_at":"2026-11-10T19:25:16+00:00","triaged_at":"2026-11-10T19:25:40+00:00","updated_at":"2026-11-10T19:30:21+00:00","category":"other","confidence":0.3,"triage":{"at":"2026-11-10T19:25:40Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Xbox: heap buffer overflow lets a network attacker run code","impact":"high","summary":"A heap-based buffer overflow in Xbox lets an unauthorized attacker reach the device over a network. The sources say the attacker can execute code.","audience":"everyone","category":"other","nicknames":[],"who_cares":["xbox"],"confidence":0.5,"fix_status":"unknown","needs_auth":"unknown","worst_case":"Attacker runs code on the Xbox over the network","analyst_note":"Check Microsoft's MSRC advisory for CVE-2026-66801 for affected Xbox models, fixed firmware or system update, and whether any user action is needed.","how_to_check":"unknown","plain_action":"","product_name":"Xbox","needs_analyst":true,"not_affected_if":[],"who_is_affected":"unknown","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.00063,"input_tokens":4485,"output_tokens":362,"severity_before":"critical"},"analyst_status":"done","analyst_note":"Check Microsoft's MSRC advisory for CVE-2026-66801 for affected Xbox models, fixed firmware or system update, and whether any user action is needed.","search":"'-2026':12A,15A '-66801':13A,16A 'allow':56C 'attack':8A,34B,45B,59C 'base':26B,51C 'buffer':3A,27B,52C 'code':10A,48B,62C 'consol':18B 'cve':11A,14A 'devic':37B 'execut':47B,61C 'heap':2A,25B,50C 'heap-bas':24B,49C 'let':5A,31B 'network':7A,19B,40B,65C 'overflow':4A,28B,53C 'rce':21B 'reach':35B 'run':9A 'say':43B 'sourc':42B 'unauthor':33B,58C 'xbox':1A,17A,22B,30B,55C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"everyone","plain_action":null,"pkeys":["xbox"],"ptokens":["xbox"],"labels":["console","critical","network","other","rce","vendor","xbox"],"campaign_type":null,"search_a":"'-2026':12A,15A '-66801':13A,16A 'attack':8A 'buffer':3A 'code':10A 'cve':11A,14A 'heap':2A 'let':5A 'network':7A 'overflow':4A 'run':9A 'xbox':1A,17A","search_b":"'attack':34B,45B 'base':26B 'buffer':27B 'code':48B 'consol':18B 'devic':37B 'execut':47B 'heap':25B 'heap-bas':24B 'let':31B 'network':19B,40B 'overflow':28B 'rce':21B 'reach':35B 'say':43B 'sourc':42B 'unauthor':33B 'xbox':22B,30B","search_c":"'allow':56C 'attack':59C 'base':51C 'buffer':52C 'code':62C 'execut':61C 'heap':50C 'heap-bas':49C 'network':65C 'overflow':53C 'unauthor':58C 'xbox':55C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:21:17+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-66801","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66801","severity":null,"published_at":"2026-11-10T19:21:17+00:00","modified_at":"2026-11-10T19:21:17+00:00","first_seen_at":"2026-11-10T19:25:16+00:00","fetched_at":"2026-11-10T19:25:16+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-66801:2515","url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66801","severity":null,"published_at":"2026-11-10T19:30:21+00:00","modified_at":"2026-11-10T19:30:21+00:00","first_seen_at":"2026-11-10T19:30:21+00:00","fetched_at":"2026-11-10T19:30:21+00:00","note":"MSRC page exists (title: Microsoft Xbox Remote Code Execution Vulnerability) but body is JS-rendered; web-cli and browser-cli could not read it. No affected models, fixed build or exploitation status confirmed. Nothing verified. Revisit when readable (try CSAF/API or cve.org).","cites":["https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66801"]}],"documents":[{"id":117570,"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66801","title":"CVE-2026-66801 - Microsoft Xbox Remote Code Execution Vulnerability (MSRC)","kind":"advisory","source":"analyst","publisher":null,"text":"MSRC page title only; body is JavaScript-rendered and could not be read.","published_at":null,"relation":"advisory","confidence":null,"note":null}],"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"}