{"id":"CVE-2025-29940","kind":"vulnerability","aliases":["CVE-2025-29940"],"related":[],"title":"AMD SEV firmware: malicious hypervisor can overwrite guest memory","description":"Unverified ownership in Secure Encrypted Virtualization (SEV) firmware could allow a privileged attacker with access to a malicious hypervisor to overwrite guest memory if segmented Reverse Map Table (RMP) is enabled potentially resulting in loss of guest data integrity.","summary":"Unverified ownership in AMD Secure Encrypted Virtualization firmware lets a privileged attacker controlling a malicious hypervisor overwrite guest memory when segmented Reverse Map Table is enabled. The result is loss of guest data integrity.","severity":"medium","cvss":5.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["amd","confidential-computing","hypervisor","infrastructure","kvm","sev"],"not_affected_if":["no-sev","segmented-rmp-disabled"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T22:17:45+00:00","first_seen_at":"2026-11-10T22:27:22+00:00","triaged_at":"2026-11-10T22:30:38+00:00","updated_at":"2026-11-10T22:30:38+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-10T22:30:38Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"AMD SEV firmware: malicious hypervisor can overwrite guest memory","impact":"medium","summary":"Unverified ownership in AMD Secure Encrypted Virtualization firmware lets a privileged attacker controlling a malicious hypervisor overwrite guest memory when segmented Reverse Map Table is enabled. The result is loss of guest data integrity.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["amd","sev","hypervisor","confidential-computing","kvm"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"hypervisor attacker overwrites guest memory, corrupting guest data integrity","analyst_note":"Find AMD's security bulletin for CVE-2025-29940 to get affected and fixed firmware versions and mitigation settings; the NVD entry alone does not provide them.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-sev","segmented-rmp-disabled"],"who_is_affected":"Systems running AMD SEV guests on AMD EPYC hosts with segmented RMP enabled, where the hypervisor could be untrusted or compromised. Hosts without SEV or with segmented RMP disabled are not described as exposed. The sources do not list affected firmware versions.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000717,"input_tokens":4556,"output_tokens":523,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2025':11A,14A '-29940':12A,15A 'access':72C 'allow':67C 'amd':1A,16B,27B 'attack':35B,70C 'comput':19B 'confidenti':18B 'confidential-comput':17B 'control':36B 'could':66C 'cve':10A,13A 'data':56B,95C 'enabl':49B,88C 'encrypt':29B,62C 'firmwar':3A,31B,65C 'guest':8A,41B,55B,79C,94C 'hypervisor':5A,20B,39B,76C 'infrastructur':21B 'integr':57B,96C 'kvm':22B 'let':32B 'loss':53B,92C 'malici':4A,38B,75C 'map':46B,84C 'memori':9A,42B,80C 'overwrit':7A,40B,78C 'ownership':25B,59C 'potenti':89C 'privileg':34B,69C 'result':51B,90C 'revers':45B,83C 'rmp':86C 'secur':28B,61C 'segment':44B,82C 'sev':2A,23B,64C 'tabl':47B,85C 'unverifi':24B,58C 'virtual':30B,63C","nicknames":[],"mitigations":[],"who_affected":"Systems running AMD SEV guests on AMD EPYC hosts with segmented RMP enabled, where the hypervisor could be untrusted or compromised. Hosts without SEV or with segmented RMP disabled are not described as exposed. The sources do not list 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","medium","sev"],"campaign_type":null,"search_a":"'-2025':11A,14A '-29940':12A,15A 'amd':1A 'cve':10A,13A 'firmwar':3A 'guest':8A 'hypervisor':5A 'malici':4A 'memori':9A 'overwrit':7A 'sev':2A","search_b":"'amd':16B,27B 'attack':35B 'comput':19B 'confidenti':18B 'confidential-comput':17B 'control':36B 'data':56B 'enabl':49B 'encrypt':29B 'firmwar':31B 'guest':41B,55B 'hypervisor':20B,39B 'infrastructur':21B 'integr':57B 'kvm':22B 'let':32B 'loss':53B 'malici':38B 'map':46B 'memori':42B 'overwrit':40B 'ownership':25B 'privileg':34B 'result':51B 'revers':45B 'secur':28B 'segment':44B 'sev':23B 'tabl':47B 'unverifi':24B 'virtual':30B","search_c":"'access':72C 'allow':67C 'attack':70C 'could':66C 'data':95C 'enabl':88C 'encrypt':62C 'firmwar':65C 'guest':79C,94C 'hypervisor':76C 'integr':96C 'loss':92C 'malici':75C 'map':84C 'memori':80C 'overwrit':78C 'ownership':59C 'potenti':89C 'privileg':69C 'result':90C 'revers':83C 'rmp':86C 'secur':61C 'segment':82C 'sev':64C 'tabl':85C 'unverifi':58C 'virtual':63C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T22:17:45+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-2025-29940","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-29940","severity":null,"published_at":"2026-11-10T22:17:45+00:00","modified_at":"2026-11-10T22:17:45+00:00","first_seen_at":"2026-11-10T22:27:22+00:00","fetched_at":"2026-11-10T22:27:22+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"}