{ "cveId": "CVE-2026-46295", "url": "https://patchblox.com/security/cve/CVE-2026-46295", "summary": "CVE-2026-46295 is fixed in 19 products on 1 platform, first by ALAS2023-2026-1754, released May 25, 2026. It is not reported as exploited. Patch Radar priority: Routine.", "title": "linux: In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Do IRR scan in __kvm_apic_update_irr e...", "description": "In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty Fall back to apic_find_highest_vector() when PID.ON is set but PIR turns out to be empty, to correctly report the highest pending interrupt from the existing IRR. In a nested VM stress test, the following WARNING fires in vmx_check_nested_events() when kvm_cpu_has_interrupt() reports a pending interrupt but the subsequent kvm_apic_has_interrupt() (which invokes vmx_sync_pir_to_irr() again) returns -1: WARNING: CPU: 99 PID: 57767 at arch/x86/kvm/vmx/nested.c:4449 vmx_check_nested_events\u002B0x6bf/0x6e0 [kvm_intel] Call Trace: kvm_check_and_inject_events vcpu_enter_guest.constprop.0 vcpu_run kvm_arch_vcpu_ioctl_run kvm_vcpu_ioctl __x64_sys_ioctl do_syscall_64 entry_SYSCALL_64_after_hwframe The root cause is a race between vmx_sync_pir_to_irr() on the target vCPU and __vmx_deliver_posted_interrupt() on a sender vCPU. The sender performs two individually-atomic operations that are not a single transaction: 1. pi_test_and_set_pir(vector) -- sets the PIR bit 2. pi_test_and_set_on() -- sets PID.ON The following interleaving triggers the bug: Sender vCPU (IPI): Target vCPU (1st sync_pir_to_irr): B1: set PIR[vector] A1: pi_clear_on() A2: pi_harvest_pir() -\u003E sees B1 bit A3: xchg() -\u003E consumes bit, PIR=0 (1st sync returns correct max_irr) B2: set PID.ON = 1 Target vCPU (2nd sync_pir_to_irr): C1: pi_test_on() -\u003E TRUE (from B2) C2: pi_clear_on() -\u003E ON=0 C3: pi_harvest_pir() -\u003E PIR empty C4: *max_irr = -1, early return IRR NOT SCANNED The interrupt is not lost (it resides in the IRR from the first sync and is recovered on the next vcpu_enter_guest() iteration), but the incorrect max_irr causes a spurious WARNING and a wasted L2 VM-Enter/VM-Exit cycle.", "published": "2026-05-25T09:00:00Z", "severity": "medium", "cvss": 5.5, "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "epss": 0.00112, "epssPercentile": 0.01402, "priority": "Routine", "priorityTier": 4, "exploited": false, "vendorExploited": false, "disclosed": false, "fixes": [ { "platform": "linux", "product": "bpftool6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "bpftool6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel-livepatch-6.18.30-61.116", "release": "amzn 2023", "fixedVersion": "1:1.0-0.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-aarch64", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-x86_64", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-headers", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra-common", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-tools", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-tools-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "kernel6.18-tools-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "linux", "release": "Debian 14", "fixedVersion": "7.0.7-1", "fix": "DEBIAN-CVE-2026-46295", "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-46295", "released": "2026-06-24T14:07:24Z" }, { "platform": "linux", "product": "perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "python3-perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" }, { "platform": "linux", "product": "python3-perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.30-61.116.amzn2023", "fix": "ALAS2023-2026-1754", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1754", "released": "2026-05-25T09:00:00Z" } ], "noFixYet": [], "dataAsOf": "2026-11-08T19:12:23Z", "attribution": { "text": "Data: Patchblox Patch Radar", "url": "https://patchblox.com/security/patch-radar", "terms": "https://patchblox.com/security/patch-radar/use-the-data" } }