{
  "cveId": "CVE-2026-89917",
  "url": "https://patchblox.com/security/cve/CVE-2026-89917",
  "summary": "CVE-2026-89917 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-89917, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping  While VNCR TLB invalidation always occurs under the MMU lock, vcpu_put() doesn\u0027t, while it unmaps the VNCR page.  The problem is that the invalidation evaluates vncr_tlb::cpu to decide whether an unmapping needs to take place (cpu != -1) before performing it. On the other hand, this_cpu_reset_vncr_fixmap() unconditionally unmaps if L1_VNCR_MAPPED is set.  These two obviously can race, with a TOCTOU pattern on the TLBI path, and a BUG_ON() on the vcpu_put() path. And the two can end-up calling vncr_fixmap(-1), with extra lethal effects.  Move the reset of vncr_tlb::cpu to -1 to a common function, and make this update atomic so that only a single thread can reset the field and perform the corresponding unmap. The vcpu_put() still need to unconditionally unmap the current VNCR to close another ugly race.  Finally, the assignment of vncr_tlb::cpu is moved to be kept in sync with the actual mapping, similar to L1_VNCR_MAPPED being set.",
  "published": "2026-09-16T11:17:00Z",
  "severity": "important",
  "epss": 0.00206,
  "epssPercentile": 0.10791,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-89917",
  "fixes": [
    {
      "platform": "linux",
      "product": "bpftool6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "bpftool6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-6.18.54-121.166",
      "release": "amzn 2023",
      "fixedVersion": "1:1.0-0.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-aarch64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-x86_64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-headers",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
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      "product": "kernel6.18-modules-extra",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra-common",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-89917",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89917",
      "released": "2026-09-23T19:19:02Z"
    },
    {
      "platform": "linux",
      "product": "microvm-kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
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      "product": "perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    },
    {
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      "release": "amzn 2023",
      "fixedVersion": "1:6.18.54-121.166.amzn2023",
      "fix": "ALAS2023-2026-3192",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3192",
      "released": "2026-11-07T01:06:07Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}