{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-46295",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-46295",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-06-08T15:46:22.494Z",
    "updatedAt": "2026-06-14T18:07:10.912Z",
    "importedAt": "2026-10-24T01:58:14.884Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "KVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty\n\nFall back to apic_find_highest_vector() when PID.ON is set but PIR\nturns out to be empty, to correctly report the highest pending interrupt\nfrom the existing IRR.\n\nIn a nested VM stress test, the following WARNING fires in\nvmx_check_nested_events() when kvm_cpu_has_interrupt() reports a pending\ninterrupt but the subsequent kvm_apic_has_interrupt() (which invokes\nvmx_sync_pir_to_irr() again) returns -1:\n\n  WARNING: CPU: 99 PID: 57767 at arch/x86/kvm/vmx/nested.c:4449 vmx_check_nested_events+0x6bf/0x6e0 [kvm_intel]\n  Call Trace:\n   kvm_check_and_inject_events\n   vcpu_enter_guest.constprop.0\n   vcpu_run\n   kvm_arch_vcpu_ioctl_run\n   kvm_vcpu_ioctl\n   __x64_sys_ioctl\n   do_syscall_64\n   entry_SYSCALL_64_after_hwframe\n\nThe root cause is a race between vmx_sync_pir_to_irr() on the target vCPU\nand __vmx_deliver_posted_interrupt() on a sender vCPU.  The sender\nperforms two individually-atomic operations that are not a single\ntransaction:\n\n  1. pi_test_and_set_pir(vector)  -- sets the PIR bit\n  2. pi_test_and_set_on()         -- sets PID.ON\n\nThe following interleaving triggers the bug:\n\n  Sender vCPU (IPI):              Target vCPU (1st sync_pir_to_irr):\n  B1: set PIR[vector]\n                                  A1: pi_clear_on()\n                                  A2: pi_harvest_pir() -> sees B1 bit\n                                  A3: xchg() -> consumes bit, PIR=0\n                                      (1st sync returns correct max_irr)\n  B2: set PID.ON = 1\n\n                                  Target vCPU (2nd sync_pir_to_irr):\n                                  C1: pi_test_on() -> TRUE (from B2)\n                                  C2: pi_clear_on() -> ON=0\n                                  C3: pi_harvest_pir() -> PIR empty\n                                  C4: *max_irr = -1, early return\n                                      IRR NOT SCANNED\n\nThe interrupt is not lost (it resides in the IRR from the first sync and\nis recovered on the next vcpu_enter_guest() iteration), but the incorrect\nmax_irr causes a spurious WARNING and a wasted L2 VM-Enter/VM-Exit cycle.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "b41f8638b9d30fbe045b4ef83ff4136c56a57397",
              "status": "affected",
              "versionType": "git",
              "lessThan": "bb1703949dcaa9a49c338dee075f659f4634214d"
            },
            {
              "version": "b41f8638b9d30fbe045b4ef83ff4136c56a57397",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4b6b06a8b12bfd95f9015074b1430c1480908073"
            },
            {
              "version": "b41f8638b9d30fbe045b4ef83ff4136c56a57397",
              "status": "affected",
              "versionType": "git",
              "lessThan": "33fd0ccd2590b470b65adcca288615ad3b5e3e06"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.16",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.16"
            },
            {
              "version": "6.18.30",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.0.7",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "version": "7.1",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}