{"id":"CVE-2025-62621","kind":"vulnerability","aliases":["CVE-2025-62621"],"related":[],"title":"AMD SEV firmware: malicious hypervisor can break SEV-SNP guest memory integrity","description":"Expected behavior violation in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to bypass Reverse Map Table (RMP) protections, potentially resulting in a loss of Secure Encrypted Virtualization-Secure Nested Paging (SEV-SNP) guest memory integrity.","summary":"AMD Secure Encrypted Virtualization firmware has an expected-behavior violation that lets a malicious hypervisor bypass Reverse Map Table protections. An attacker controlling the hypervisor could alter memory of SEV-SNP guests, losing their memory integrity.","severity":"medium","cvss":5.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["amd","confidential-computing","hypervisor","infrastructure","sev-snp"],"not_affected_if":["managed-hosting","no-sev-snp"],"how_to_check":"- Check whether hosts run AMD EPYC processors with SEV-SNP enabled for confidential VMs, for example by reviewing the hypervisor and host firmware versions.","fix":null,"status":"open","published_at":"2026-11-10T22:17:47+00:00","first_seen_at":"2026-11-10T22:27:23+00:00","triaged_at":"2026-11-10T22:30:34+00:00","updated_at":"2026-11-10T22:30:34+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-10T22:30:34Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"AMD SEV firmware: malicious hypervisor can break SEV-SNP guest memory integrity","impact":"medium","summary":"AMD Secure Encrypted Virtualization firmware has an expected-behavior violation that lets a malicious hypervisor bypass Reverse Map Table protections. An attacker controlling the hypervisor could alter memory of SEV-SNP guests, losing their memory integrity.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["amd","sev-snp","confidential-computing","hypervisor"],"confidence":0.6,"fix_status":"unknown","needs_auth":"unknown","worst_case":"Guest memory integrity lost under a malicious hypervisor","analyst_note":"Find AMD's security bulletin for CVE-2025-62621 to get affected firmware versions and the fixed version.","how_to_check":"- Check whether hosts run AMD EPYC processors with SEV-SNP enabled for confidential VMs, for example by reviewing the hypervisor and host firmware versions.\n- unknown for specific firmware versions: the sources do not say.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-sev-snp","managed-hosting"],"who_is_affected":"Only operators running confidential VMs with AMD SEV-SNP on AMD hardware are exposed, and the flaw requires a malicious or compromised hypervisor to be exploited. The sources do not list affected firmware versions or a fix, so the vendor's advisory must be checked for those details.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000751,"input_tokens":4578,"output_tokens":587,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2025':15A,18A '-62621':16A,19A 'allow':78C 'alter':56B 'amd':1A,20B,29B,71C 'attack':51B 'behavior':38B,68C 'break':7A 'bypass':45B,83C 'comput':23B 'confidenti':22B 'confidential-comput':21B 'control':52B 'could':55B,77C 'cve':14A,17A 'encrypt':31B,73C,96C 'expect':37B,67C 'expected-behavior':36B 'firmwar':3A,33B,76C 'guest':11A,62B,105C 'hypervisor':5A,24B,44B,54B,81C 'infrastructur':25B 'integr':13A,66B,107C 'let':41B 'lose':63B 'loss':93C 'malici':4A,43B,80C 'map':47B,85C 'memori':12A,57B,65B,106C 'nest':100C 'page':101C 'potenti':89C 'protect':49B,88C 'result':90C 'revers':46B,84C 'rmp':87C 'secur':30B,72C,95C,99C 'sev':2A,9A,27B,60B,75C,103C 'sev-snp':8A,26B,59B,102C 'snp':10A,28B,61B,104C 'tabl':48B,86C 'violat':39B,69C 'virtual':32B,74C,98C 'virtualization-secur':97C","nicknames":[],"mitigations":[],"who_affected":"Only operators running confidential VMs with AMD SEV-SNP on AMD hardware are exposed, and the flaw requires a malicious or compromised hypervisor to be exploited. The sources do not list affected firmware versions or a fix, so the vendor's advisory must be checked for those details.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["amd","confidentialcomputing","hypervisor","infrastructure","medium","sevsnp"],"campaign_type":null,"search_a":"'-2025':15A,18A '-62621':16A,19A 'amd':1A 'break':7A 'cve':14A,17A 'firmwar':3A 'guest':11A 'hypervisor':5A 'integr':13A 'malici':4A 'memori':12A 'sev':2A,9A 'sev-snp':8A 'snp':10A","search_b":"'alter':56B 'amd':20B,29B 'attack':51B 'behavior':38B 'bypass':45B 'comput':23B 'confidenti':22B 'confidential-comput':21B 'control':52B 'could':55B 'encrypt':31B 'expect':37B 'expected-behavior':36B 'firmwar':33B 'guest':62B 'hypervisor':24B,44B,54B 'infrastructur':25B 'integr':66B 'let':41B 'lose':63B 'malici':43B 'map':47B 'memori':57B,65B 'protect':49B 'revers':46B 'secur':30B 'sev':27B,60B 'sev-snp':26B,59B 'snp':28B,61B 'tabl':48B 'violat':39B 'virtual':32B","search_c":"'allow':78C 'amd':71C 'behavior':68C 'bypass':83C 'could':77C 'encrypt':73C,96C 'expect':67C 'firmwar':76C 'guest':105C 'hypervisor':81C 'integr':107C 'loss':93C 'malici':80C 'map':85C 'memori':106C 'nest':100C 'page':101C 'potenti':89C 'protect':88C 'result':90C 'revers':84C 'rmp':87C 'secur':72C,95C,99C 'sev':75C,103C 'sev-snp':102C 'snp':104C 'tabl':86C 'violat':69C 'virtual':74C,98C 'virtualization-secur':97C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T22:17:47+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: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-2025-62621","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-62621","severity":null,"published_at":"2026-11-10T22:17:47+00:00","modified_at":"2026-11-10T22:17:47+00:00","first_seen_at":"2026-11-10T22:27:23+00:00","fetched_at":"2026-11-10T22:27:23+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"}