CVE-2026-98546
In the Linux kernel, the following vulnerability has been resolved:
arm64/boot: Disable trapping of PMZR_EL0 writes to EL2
__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message.
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Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits.
CVSS
NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days
- 0.20 %
- Percentile among all scored CVEs
- 9
- Score date
- 10/20/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
References
Show 4 references
Raw JSON (NVD)
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{
"id": "CVE-2026-98546",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "686d8f7b592f3466f44aea653c8147611b351c83",
"lessThan": "bb8c90c86441c090e9036f019cf1b4d7894a2c40",
"versionType": "git"
},
{
"status": "affected",
"version": "858c7bfcb35e1100b58bb63c9f562d86e09418d9",
"lessThan": "071f51188a5d8ec10535541255587976d12fc7d8",
"versionType": "git"
},
{
"status": "affected",
"version": "858c7bfcb35e1100b58bb63c9f562d86e09418d9",
"lessThan": "ce71865bf43f88bed9d9218e9218e537150be506",
"versionType": "git"
},
{
"status": "affected",
"version": "858c7bfcb35e1100b58bb63c9f562d86e09418d9",
"lessThan": "2bc6b218717b9d08f466f88209251d54bc09b207",
"versionType": "git"
},
{
"status": "affected",
"version": "882f78400322c0aec4b641a7168adad9a66bc0c2",
"versionType": "git"
},
{
"status": "affected",
"version": "6.12.25",
"lessThan": "6.12.112",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.14.4",
"lessThan": "6.15",
"versionType": "semver"
}
],
"programFiles": [
"Documentation/arch/arm64/booting.rst",
"arch/arm64/include/asm/el2_setup.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"Documentation/arch/arm64/booting.rst",
"arch/arm64/include/asm/el2_setup.h"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:06.517",
"references": [
{
"url": "https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64/boot: Disable trapping of PMZR_EL0 writes to EL2\n\n__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.\nPMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in\nHDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host\ntraps to EL2, where the nVHE hypervisor has no handler and BUG()s. The\nkernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU\ndriver set PMUSERENR_EL0.UEN for a task with a user-read event, so a\nwrite from EL0 reaches the trap and takes the host down without a panic\nmessage.\n\nAccumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already\ndoes for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9\nbits."
}
],
"lastModified": "2026-10-19T10:19:10.600",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}