{"id":"CVE-2026-28249","kind":"vulnerability","aliases":["CVE-2026-28249"],"related":[],"title":"AMD SEV firmware: hypervisor can corrupt guest memory cache coherency","description":"Improper preservation of consistency between independent representations of shared state in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to potentially affect cache coherency for guest context pages resulting in loss of integrity.","summary":"AMD Secure Encrypted Virtualization (SEV) firmware fails to keep independent copies of shared state consistent. A malicious hypervisor could affect cache coherency for guest context pages, causing loss of data integrity inside protected virtual machines.","severity":"medium","cvss":4.6,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["amd","confidential-computing","hypervisor","infrastructure","kvm","linux","sev"],"not_affected_if":["no-sev-guests","non-amd-hardware"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T22:18:32+00:00","first_seen_at":"2026-11-10T22:27:30+00:00","triaged_at":"2026-11-10T22:30:59+00:00","updated_at":"2026-11-10T22:30:59+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-10T22:30:59Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"AMD SEV firmware: hypervisor can corrupt guest memory cache coherency","impact":"medium","summary":"AMD Secure Encrypted Virtualization (SEV) firmware fails to keep independent copies of shared state consistent. A malicious hypervisor could affect cache coherency for guest context pages, causing loss of data integrity inside protected virtual machines.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["amd","sev","confidential-computing","hypervisor","kvm","linux"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"guest VM memory integrity lost under a malicious hypervisor","analyst_note":"Find AMD's security bulletin for CVE-2026-28249 to get affected firmware versions and fixed releases.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-sev-guests","non-amd-hardware"],"who_is_affected":"Organizations running AMD EPYC servers with SEV or SEV-SNP confidential virtual machines on a hypervisor. The flaw requires a malicious hypervisor, so teams that do not run SEV guests or trust their hypervisor's operator are lower risk. The sources do not name affected firmware versions.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000708,"input_tokens":4532,"output_tokens":510,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-28249':13A,16A 'affect':45B,85C 'allow':79C 'amd':1A,17B,26B,72C 'cach':9A,46B,86C 'caus':52B 'coher':10A,47B,87C 'comput':20B 'confidenti':19B 'confidential-comput':18B 'consist':40B,64C 'context':50B,90C 'copi':36B 'corrupt':6A 'could':44B,78C 'cve':11A,14A 'data':55B 'encrypt':28B,74C 'fail':32B 'firmwar':3A,31B,77C 'guest':7A,49B,89C 'hypervisor':4A,21B,43B,82C 'improp':61C 'independ':35B,66C 'infrastructur':22B 'insid':57B 'integr':56B,96C 'keep':34B 'kvm':23B 'linux':24B 'loss':53B,94C 'machin':60B 'malici':42B,81C 'memori':8A 'page':51B,91C 'potenti':84C 'preserv':62C 'protect':58B 'represent':67C 'result':92C 'secur':27B,73C 'sev':2A,25B,30B,76C 'share':38B,69C 'state':39B,70C 'virtual':29B,59B,75C","nicknames":[],"mitigations":[],"who_affected":"Organizations running AMD EPYC servers with SEV or SEV-SNP confidential virtual machines on a hypervisor. The flaw requires a malicious hypervisor, so teams that do not run SEV guests or trust their hypervisor's operator are lower risk. The sources do not name affected firmware versions.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["amd","confidentialcomputing","hypervisor","infrastructure","kvm","linux","medium","sev"],"campaign_type":null,"search_a":"'-2026':12A,15A '-28249':13A,16A 'amd':1A 'cach':9A 'coher':10A 'corrupt':6A 'cve':11A,14A 'firmwar':3A 'guest':7A 'hypervisor':4A 'memori':8A 'sev':2A","search_b":"'affect':45B 'amd':17B,26B 'cach':46B 'caus':52B 'coher':47B 'comput':20B 'confidenti':19B 'confidential-comput':18B 'consist':40B 'context':50B 'copi':36B 'could':44B 'data':55B 'encrypt':28B 'fail':32B 'firmwar':31B 'guest':49B 'hypervisor':21B,43B 'independ':35B 'infrastructur':22B 'insid':57B 'integr':56B 'keep':34B 'kvm':23B 'linux':24B 'loss':53B 'machin':60B 'malici':42B 'page':51B 'protect':58B 'secur':27B 'sev':25B,30B 'share':38B 'state':39B 'virtual':29B,59B","search_c":"'affect':85C 'allow':79C 'amd':72C 'cach':86C 'coher':87C 'consist':64C 'context':90C 'could':78C 'encrypt':74C 'firmwar':77C 'guest':89C 'hypervisor':82C 'improp':61C 'independ':66C 'integr':96C 'loss':94C 'malici':81C 'page':91C 'potenti':84C 'preserv':62C 'represent':67C 'result':92C 'secur':73C 'sev':76C 'share':69C 'state':70C 'virtual':75C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T22:18:32+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"psirt@amd.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-28249","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28249","severity":null,"published_at":"2026-11-10T22:18:32+00:00","modified_at":"2026-11-10T22:18:32+00:00","first_seen_at":"2026-11-10T22:27:30+00:00","fetched_at":"2026-11-10T22:27:30+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"}