{"id":"CVE-2026-0480","kind":"vulnerability","aliases":["CVE-2026-0480"],"related":[],"title":"AMD SEV firmware: missing authentication lets a hypervisor forge guest messages","description":"Missing Authentication for Critical Function in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to forge SEV-TIO guest request messages potentially compromising SEV-SNP guest memory integrity and confidentiality.","summary":"AMD Secure Encrypted Virtualization (SEV) firmware does not authenticate a critical function, so a malicious hypervisor can forge SEV-TIO guest request messages. This could compromise the memory integrity and confidentiality of SEV-SNP guests.","severity":"medium","cvss":6.0,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["amd","confidential-computing","hypervisor","infrastructure","linux-kvm","sev-snp"],"not_affected_if":["no-sev-snp-guests","no-sev-tio"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T23:17:19+00:00","first_seen_at":"2026-11-10T23:27:36+00:00","triaged_at":"2026-11-10T23:28:49+00:00","updated_at":"2026-11-10T23:28:49+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-10T23:28:49Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"AMD SEV firmware: missing authentication lets a hypervisor forge guest messages","impact":"high","summary":"AMD Secure Encrypted Virtualization (SEV) firmware does not authenticate a critical function, so a malicious hypervisor can forge SEV-TIO guest request messages. This could compromise the memory integrity and confidentiality of SEV-SNP guests.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["amd","sev-snp","confidential-computing","hypervisor","linux-kvm"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"Malicious hypervisor forges guest messages, compromising SEV-SNP guest memory","analyst_note":"Find AMD's security bulletin for CVE-2026-0480 to get affected firmware versions and the fixed version; the NVD entry alone does not give them.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-sev-snp-guests","no-sev-tio"],"who_is_affected":"Affects AMD EPYC hosts running SEV-SNP confidential guests with SEV-TIO enabled, where the hypervisor is the attacker. Operators of cloud or on-premise confidential computing platforms should look at this; teams without SEV-SNP guests can skip it. The sources do not give the affected firmware versions.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000729,"input_tokens":4551,"output_tokens":547,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-0480':14A,17A '-2026':13A,16A 'allow':80C 'amd':1A,18B,30B,73C 'authent':5A,38B,68C 'compromis':56B,93C 'comput':21B 'confidenti':20B,61B,101C 'confidential-comput':19B 'could':55B,79C 'critic':40B,70C 'cve':12A,15A 'encrypt':32B,75C 'firmwar':3A,35B,78C 'forg':9A,47B,85C 'function':41B,71C 'guest':10A,51B,66B,89C,97C 'hypervisor':8A,22B,45B,83C 'infrastructur':23B 'integr':59B,99C 'kvm':26B 'let':6A 'linux':25B 'linux-kvm':24B 'malici':44B,82C 'memori':58B,98C 'messag':11A,53B,91C 'miss':4A,67C 'potenti':92C 'request':52B,90C 'secur':31B,74C 'sev':2A,28B,34B,49B,64B,77C,87C,95C 'sev-snp':27B,63B,94C 'sev-tio':48B,86C 'snp':29B,65B,96C 'tio':50B,88C 'virtual':33B,76C","nicknames":[],"mitigations":[],"who_affected":"Affects AMD EPYC hosts running SEV-SNP confidential guests with SEV-TIO enabled, where the hypervisor is the attacker. Operators of cloud or on-premise confidential computing platforms should look at this; teams without SEV-SNP guests can skip it. The sources do not give the 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","linuxkvm","medium","sevsnp"],"campaign_type":null,"search_a":"'-0480':14A,17A '-2026':13A,16A 'amd':1A 'authent':5A 'cve':12A,15A 'firmwar':3A 'forg':9A 'guest':10A 'hypervisor':8A 'let':6A 'messag':11A 'miss':4A 'sev':2A","search_b":"'amd':18B,30B 'authent':38B 'compromis':56B 'comput':21B 'confidenti':20B,61B 'confidential-comput':19B 'could':55B 'critic':40B 'encrypt':32B 'firmwar':35B 'forg':47B 'function':41B 'guest':51B,66B 'hypervisor':22B,45B 'infrastructur':23B 'integr':59B 'kvm':26B 'linux':25B 'linux-kvm':24B 'malici':44B 'memori':58B 'messag':53B 'request':52B 'secur':31B 'sev':28B,34B,49B,64B 'sev-snp':27B,63B 'sev-tio':48B 'snp':29B,65B 'tio':50B 'virtual':33B","search_c":"'allow':80C 'amd':73C 'authent':68C 'compromis':93C 'confidenti':101C 'could':79C 'critic':70C 'encrypt':75C 'firmwar':78C 'forg':85C 'function':71C 'guest':89C,97C 'hypervisor':83C 'integr':99C 'malici':82C 'memori':98C 'messag':91C 'miss':67C 'potenti':92C 'request':90C 'secur':74C 'sev':77C,87C,95C 'sev-snp':94C 'sev-tio':86C 'snp':96C 'tio':88C 'virtual':76C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T23:17:19+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/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-2026-0480","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-0480","severity":null,"published_at":"2026-11-10T23:17:19+00:00","modified_at":"2026-11-10T23:17:19+00:00","first_seen_at":"2026-11-10T23:27:36+00:00","fetched_at":"2026-11-10T23:27:36+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"}