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CVE-2026-72397 (GCVE-0-2026-72397)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:56 – Updated: 2026-08-17 05:43
VLAI
Title
hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()
Summary
In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid() pmbus_data2reg_vid() hardcoded the VR11 encoding regardless of the vrm_version configured by the driver, while pmbus_reg2data_vid() already switched on it. Any driver that selects a non-VR11 VID mode and exposes a regulator (or hwmon vout setter) sent dangerously wrong codes to PMBUS_VOUT_COMMAND -- e.g. an nvidia195mv part asked for 200 mV got the VR11 clamp to 500 mV encoded as 0xB2, which the chip interprets as 1080 mV. Mirror pmbus_reg2data_vid() so writes round-trip with reads.
Severity
7.1 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 068c227056b9223fea1a759e08db2558d5cbb5ad , < 5bd0d47640395f8a8c34446b62d1781b88869dfa (git)
Affected: 068c227056b9223fea1a759e08db2558d5cbb5ad , < 828cd614e2af053ca5e1d6da767bbd8a1b5cabfb (git)
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Linux Linux Affected: 4.3
Unaffected: 0 , < 4.3 (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hwmon/pmbus/pmbus_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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          "versions": [
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              "version": "4.3"
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              "versionType": "original_commit_for_fix"
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      "cpeApplicability": [
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          "nodes": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "4.3",
                  "vulnerable": true
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()\n\npmbus_data2reg_vid() hardcoded the VR11 encoding regardless of the\nvrm_version configured by the driver, while pmbus_reg2data_vid()\nalready switched on it. Any driver that selects a non-VR11 VID mode\nand exposes a regulator (or hwmon vout setter) sent dangerously\nwrong codes to PMBUS_VOUT_COMMAND -- e.g. an nvidia195mv part asked\nfor 200 mV got the VR11 clamp to 500 mV encoded as 0xB2, which the\nchip interprets as 1080 mV.\n\nMirror pmbus_reg2data_vid() so writes round-trip with reads."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is only reached from local host interfaces\u2014writable hwmon sysfs attributes (pmbus_set_sensor) and the PMBus regulator set_voltage path (pmbus_regulator_set_voltage)\u2014which encode values and issue I2C PMBUS_VOUT_COMMAND writes; there is no network, adjacent-radio, or direct physical-access entry point.\nAC:L - On systems with non-VR11 VID PMBus controllers (VR12/VR13/IMVP9/AMD/nvidia195mv), any voltage-setting write deterministically uses the wrong VR11 encoding with no race, timing window, or uncontrollable memory layout; the attacker fully controls the written millivolt value and can repeat the operation reliably.\nPR:L - Writable hwmon limit attributes are exposed as mode 0644 with no capability check in pmbus_set_sensor, so a local uid-0 context (including user-namespace root or container root with /sys access) can drive the bad encoding; regulator consumers can also be influenced from ordinary local workloads on affected server/GPU platforms.\nUI:N - Exploitation requires only the attacker (or attacker-controlled software) to write hwmon voltage limits or invoke regulator voltage changes; no separate victim interaction such as plugging hardware or approving a prompt is needed.\nS:U - Impact is confined to misprogramming PMBus voltage rails on the same host kernel authority; it does not cross VM, IOMMU, or sandbox boundaries and is not a guest-to-host escape.\nC:N - This is a write-side VID encoding logic error, not kernel memory corruption; reads use the correct pmbus_reg2data_vid path and the flaw does not disclose kernel pointers, arbitrary memory, or other confidential data.\nI:H - Incorrect VID-to-register conversion sends dangerously wrong PMBUS_VOUT_COMMAND values to hardware (e.g., 200 mV requested on nvidia195mv becomes 1080 mV applied), corrupting critical CPU/GPU/board power-rail configuration and potentially causing permanent hardware damage.\nA:H - Severe over- or under-voltage on core power rails can trigger immediate hardware protection shutdowns, system hangs/resets, and sustained denial of service on data-center, HPC, and GPU server deployments using affected PMBus VRM controllers."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:43:39.708Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5bd0d47640395f8a8c34446b62d1781b88869dfa"
        },
        {
          "url": "https://git.kernel.org/stable/c/828cd614e2af053ca5e1d6da767bbd8a1b5cabfb"
        }
      ],
      "title": "hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()",
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72397",
    "datePublished": "2026-08-15T05:56:23.675Z",
    "dateReserved": "2026-08-09T03:40:39.924Z",
    "dateUpdated": "2026-08-17T05:43:39.708Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-72397",
      "date": "2026-09-05",
      "epss": "0.00151",
      "percentile": "0.04596"
    },
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      "cve": "CVE-2026-72397",
      "id": "msrc_CVE-2026-72397",
      "initial_release_date": "2026-08-23T14:52:08.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-72397.json",
      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-72397\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T06:22:13.270\",\"lastModified\":\"2026-08-17T06:19:06.263\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nhwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()\\n\\npmbus_data2reg_vid() hardcoded the VR11 encoding regardless of the\\nvrm_version configured by the driver, while pmbus_reg2data_vid()\\nalready switched on it. Any driver that selects a non-VR11 VID mode\\nand exposes a regulator (or hwmon vout setter) sent dangerously\\nwrong codes to PMBUS_VOUT_COMMAND -- e.g. an nvidia195mv part asked\\nfor 200 mV got the VR11 clamp to 500 mV encoded as 0xB2, which the\\nchip interprets as 1080 mV.\\n\\nMirror pmbus_reg2data_vid() so writes round-trip with reads.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/hwmon/pmbus/pmbus_core.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"068c227056b9223fea1a759e08db2558d5cbb5ad\",\"lessThan\":\"5bd0d47640395f8a8c34446b62d1781b88869dfa\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"068c227056b9223fea1a759e08db2558d5cbb5ad\",\"lessThan\":\"828cd614e2af053ca5e1d6da767bbd8a1b5cabfb\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/hwmon/pmbus/pmbus_core.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"4.3\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"4.3\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.2}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/5bd0d47640395f8a8c34446b62d1781b88869dfa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/828cd614e2af053ca5e1d6da767bbd8a1b5cabfb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-18T15:16:42+00:00",
      "cve": "CVE-2026-72397",
      "id": "CVE-2026-72397",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "232",
      "product_status:known_not_affected": "42",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72397.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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