{"id":"CVE-2026-0004","kind":"vulnerability","aliases":["CVE-2026-0004"],"related":[],"title":"AMD processors: transient execution flaw leaks L1 cache data across privilege boundaries","description":"A transient execution vulnerability in some AMD processors may allow an attacker with the ability to execute code on the system to infer data in the L1D cache, potentially resulting in the leakage of sensitive information across privileged boundaries.","summary":"Some AMD processors have a transient execution flaw that lets code running on the system infer data held in the L1 data cache. An attacker who can already run code on the machine can read sensitive information across privileged boundaries.","severity":"medium","cvss":5.7,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"AMD processors","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["amd","cpu","infrastructure","multi-tenant","virtualization"],"not_affected_if":["no-untrusted-code-execution","non-amd-hardware"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-12T19:16:45+00:00","first_seen_at":"2026-11-12T19:40:13+00:00","triaged_at":"2026-11-12T19:41:00+00:00","updated_at":"2026-11-12T19:41:00+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-12T19:41:00Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"AMD processors: transient execution flaw leaks L1 cache data across privilege boundaries","impact":"medium","summary":"Some AMD processors have a transient execution flaw that lets code running on the system infer data held in the L1 data cache. An attacker who can already run code on the machine can read sensitive information across privileged boundaries.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["amd","cpu","multi-tenant","virtualization"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"Code on the machine reads sensitive data across privilege boundaries","analyst_note":"Find the AMD security bulletin and list of affected processor models and fixed microcode or firmware versions; the linked Google Cloud bulletin may name them.","how_to_check":"- unknown","plain_action":"","product_name":"AMD processors","needs_analyst":true,"not_affected_if":["non-amd-hardware","no-untrusted-code-execution"],"who_is_affected":"Systems running on affected AMD processors where untrusted code can execute, such as shared hosts, multi-tenant cloud machines or virtual machine hosts. The sources do not list the affected processor models or firmware versions. Systems where only trusted code runs can likely deprioritise this, but the sources do not say.","user_interaction":"no","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000721,"input_tokens":4591,"output_tokens":524,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-0004':15A,18A '-2026':14A,17A 'abil':82C 'across':10A,65B,104C 'allow':77C 'alreadi':55B 'amd':1A,19A,21B,29B,74C 'attack':52B,79C 'boundari':12A,67B,106C 'cach':8A,50B,95C 'code':38B,57B,85C 'cpu':22B 'cve':13A,16A 'data':9A,44B,49B,91C 'execut':4A,34B,70C,84C 'flaw':5A,35B 'held':45B 'infer':43B,90C 'inform':64B,103C 'infrastructur':23B 'l1':7A,48B 'l1d':94C 'leak':6A 'leakag':100C 'let':37B 'machin':60B 'may':76C 'multi':25B 'multi-ten':24B 'potenti':96C 'privileg':11A,66B,105C 'processor':2A,30B,75C 'processors':20A 'read':62B 'result':97C 'run':39B,56B 'sensit':63B,102C 'system':42B,88C 'tenant':26B 'transient':3A,33B,69C 'virtual':27B 'vulner':71C","nicknames":[],"mitigations":[],"who_affected":"Systems running on affected AMD processors where untrusted code can execute, such as shared hosts, multi-tenant cloud machines or virtual machine hosts. The sources do not list the affected processor models or firmware versions. Systems where only trusted code runs can likely deprioritise this, but the sources do not say.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":["amdprocessors","processors"],"ptokens":["amd","processors"],"labels":["amd","cpu","infrastructure","medium","multitenant","vendor","virtualization"],"campaign_type":null,"search_a":"'-0004':15A,18A '-2026':14A,17A 'across':10A 'amd':1A,19A 'boundari':12A 'cach':8A 'cve':13A,16A 'data':9A 'execut':4A 'flaw':5A 'l1':7A 'leak':6A 'privileg':11A 'processor':2A 'processors':20A 'transient':3A","search_b":"'across':65B 'alreadi':55B 'amd':21B,29B 'attack':52B 'boundari':67B 'cach':50B 'code':38B,57B 'cpu':22B 'data':44B,49B 'execut':34B 'flaw':35B 'held':45B 'infer':43B 'inform':64B 'infrastructur':23B 'l1':48B 'let':37B 'machin':60B 'multi':25B 'multi-ten':24B 'privileg':66B 'processor':30B 'read':62B 'run':39B,56B 'sensit':63B 'system':42B 'tenant':26B 'transient':33B 'virtual':27B","search_c":"'abil':82C 'across':104C 'allow':77C 'amd':74C 'attack':79C 'boundari':106C 'cach':95C 'code':85C 'data':91C 'execut':70C,84C 'infer':90C 'inform':103C 'l1d':94C 'leakag':100C 'may':76C 'potenti':96C 'privileg':105C 'processor':75C 'result':97C 'sensit':102C 'system':88C 'transient':69C 'vulner':71C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T01:46:31+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/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-2026-0004","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-0004","severity":null,"published_at":"2026-11-12T19:16:45+00:00","modified_at":"2026-11-12T19:24:37+00:00","first_seen_at":"2026-11-12T19:40:13+00:00","fetched_at":"2026-11-12T19:40:13+00:00","note":null}],"documents":[{"id":117009,"url":"https://docs.cloud.google.com/support/bulletins/index#gcp-2026-081","title":"Google Cloud Security Bulletins: GCP-2026-081: Published: 2026-11-10 Description Description Severity Notes AMD has disclosed three vulnerabilities that affect 5th generation AMD EPYC pro","kind":"vendor","source":"vendor","publisher":null,"text":"GCP-2026-081\n\nPublished: 2026-11-10 Description Description Severity Notes AMD has disclosed three vulnerabilities that affect 5th generation AMD EPYC processors (code-named Turin): CVE-2024-36350 and CVE-2024-36357, which AMD previously disclosed for earlier EPYC processors, and a new vulnerability, CVE-2026-0004. Under certain conditions, an attacker could infer data from the store queue or the L1 data cache, potentially leaking sensitive information across privilege boundaries. Affected Compute Engine machine series: C4D, N4D, H4D, Z4D, and G4, including C4D and Z4D bare metal instances. Google has applied mitigations that protect against attacks between VMs and between VMs and the host. To protect against attacks inside a VM, such as between processes, you need to update your guest operating system. What should I do? VMs: Update your guest operating system when your OS vendor releases fixes. Starting November 10th, Google will update the CPU information that VMs report so that patched guest kernels can turn on their mitigations. After the update reaches your VM, stop and start the VM. Rebooting the guest OS isn't enough. Bare metal and nested virtualization: If you run your own OS or hypervisor on a bare metal instance, apply your vendor's fixes when they're available. If you run a hypervisor inside a VM, Google will update the CPU information that VMs report so that patched guest kernels can turn on their mitigations. After the update reaches your VM, stop and start the VM. Rebooting the guest OS isn't enough. GKE: Updated GKE node images for Turin-based bare metal instances will be made available. Upgrading your nodes picks up the CPU information update. This bulletin will be updated once the new node image is available. Cloud Run: No action is required. For more information, see AMD security bulletins AMD-SB-7073 and AMD-SB-3055 . What vulnerabilities are being addressed? CVE-2024-36350 (TSA-SQ): may allow an attacker to infer data from previous stores, potentially leaking sensitive information. CVE-2024-36357 (TSA-L1): may allow an attacker to infer data in the L1 data cache, potentially leaking sensitive information across privilege boundaries. CVE-2026-0004: may allow an attacker to infer data in the L1 data cache, potentially leaking sensitive information across privilege boundaries. These are Transient Scheduler Attacks (TSA), a type of side-channel vulnerability. Under certain conditions, the processor can briefly use data before confirming it's valid. An attacker running code on the same processor core may be able to measure the resulting timing differences to infer data from another process, the kernel, another VM, or the host. Medium CVE-2024-36350 CVE-2024-36357 CVE-2026-0004","published_at":"2026-11-10T01:46:31+00:00","relation":"mentions","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"}