{"id":"CVE-2026-99099","kind":"vulnerability","aliases":["CVE-2026-99099"],"related":[],"title":"Linux kernel: AMD CPU may skip TLB invalidation, leaving stale mappings","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/CPU/AMD: Fix AMD TLBI Erratum #1718\n\nThe processor may fail to invalidate a TLB entry while executing an\nINVLPGB/TLBSYNC instruction pair.\n\nDetect the erratum and apply a software workaround when a microcode fix\nis not present.","summary":"On some AMD processors, an INVLPGB/TLBSYNC instruction pair can fail to invalidate a TLB entry. The kernel now detects the erratum and applies a software workaround when no microcode fix is present.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["amd-x86","infrastructure","linux-kernel","self-hosted"],"not_affected_if":["non-amd-hardware"],"how_to_check":"- unknown","fix":"- Update to a Linux kernel release that includes the x86/CPU/AMD erratum #1718 fix\n- Install the latest AMD microcode package if one is available for the processor","status":"open","published_at":"2026-10-26T15:16:48+00:00","first_seen_at":"2026-10-26T16:02:26+00:00","triaged_at":"2026-10-26T16:04:02+00:00","updated_at":"2026-10-26T16:04:02+00:00","category":"infrastructure","confidence":0.4,"triage":{"at":"2026-10-26T16:04:02Z","model":"claude-haiku-5-5","output":{"fix":"- Update to a Linux kernel release that includes the x86/CPU/AMD erratum #1718 fix\n- Install the latest AMD microcode package if one is available for the processor","reach":"local","title":"Linux kernel: AMD CPU may skip TLB invalidation, leaving stale mappings","impact":"low","summary":"On some AMD processors, an INVLPGB/TLBSYNC instruction pair can fail to invalidate a TLB entry. The kernel now detects the erratum and applies a software workaround when no microcode fix is present.","category":"infrastructure","nicknames":[],"who_cares":["linux-kernel","amd-x86","self-hosted"],"confidence":0.4,"needs_auth":"unknown","worst_case":"unknown","analyst_note":"Find the AMD processor models covered by erratum #1718 and the security impact of stale TLB entries in the kernel commit or AMD advisory.","how_to_check":"- unknown","needs_analyst":true,"not_affected_if":["non-amd-hardware"],"who_is_affected":"Systems running Linux on AMD x86 processors affected by erratum #1718, where the microcode fix is absent. The sources do not say which AMD models are affected, or what an attacker could do with stale TLB entries. Teams on non-AMD hardware can skip it.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000582,"input_tokens":3347,"output_tokens":495,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-99099':14A,17A '1718':75C 'amd':3A,19B,30B,72C 'amd-x86':18B 'appli':50B,95C 'cpu':4A 'cve':12A,15A 'detect':46B,91C 'entri':42B,84C 'erratum':48B,74C,93C 'execut':86C 'fail':37B,79C 'fix':57B,71C,102C 'follow':65C 'host':27B 'infrastructur':21B 'instruct':34B,89C 'invalid':8A,39B,81C 'invlpgb/tlbsync':33B,88C 'kernel':2A,24B,44B,63C 'leav':9A 'linux':1A,23B,62C 'linux-kernel':22B 'map':11A 'may':5A,78C 'microcod':56B,101C 'pair':35B,90C 'present':59B,105C 'processor':31B,77C 'resolv':69C 'self':26B 'self-host':25B 'skip':6A 'softwar':52B,97C 'stale':10A 'tlb':7A,41B,83C 'tlbi':73C 'vulner':66C 'workaround':53B,98C 'x86':20B 'x86/cpu/amd':70C","nicknames":[],"mitigations":[],"who_affected":"Systems running Linux on AMD x86 processors affected by erratum #1718, where the microcode fix is absent. The sources do not say which AMD models are affected, or what an attacker could do with stale TLB entries. Teams on non-AMD hardware can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-26T15:16:48+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-99099","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99099","severity":null,"published_at":"2026-10-26T15:16:48+00:00","modified_at":"2026-10-26T15:16:48+00:00","first_seen_at":"2026-10-26T16:02:26+00:00","fetched_at":"2026-10-26T16:02:26+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}