{
  "cveId": "CVE-2026-89981",
  "url": "https://patchblox.com/security/cve/CVE-2026-89981",
  "summary": "CVE-2026-89981 is fixed in linux on 1 platform by DEBIAN-CVE-2026-89981 (version 7.2.6-1), released September 23, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  arm64: Don\u0027t read GMID_EL1 when MTE is disabled...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  arm64: Don\u0027t read GMID_EL1 when MTE is disabled  __cpuinfo_store_cpu() gates the GMID_EL1 read on the raw ID_AA64PFR1_EL1, so it reads the register even when the kernel has disabled MTE (CONFIG_ARM64_MTE=n or arm64.nomte). KVM sets HCR_EL2.TID5 in that case, and pKVM injects an UNDEF the host cannot handle:    Internal error: Oops - Undefined instruction: 0000000002000000 [#1]  SMP   pc : __cpuinfo_store_cpu\u002B0xf4/0x264   Kernel panic - not syncing: Attempted to kill the idle task!  Only pKVM reaches it, and only after a CPU is offlined and brought back online: its CPU_ON relay sets the host HCR before the CPU enters EL1, while plain nVHE sets it at CPUHP_AP_KVM_ONLINE.  Gate the read on the CPU\u0027s own ID_AA64PFR1_EL1 with the command-line override applied, and on CONFIG_ARM64_MTE, which no register reflects. The boot CPU stores its registers before init_cpu_features() strips an unsafe override, so clamp against the hardware value here too.",
  "published": "2026-09-16T11:17:09Z",
  "severity": "",
  "epss": 0.00198,
  "epssPercentile": 0.09568,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-89981",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89981",
      "released": "2026-09-23T19:19:02Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}