Vulnerability-Lookup

GHSA-XRXG-RJQM-5PR4

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-72397"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:13Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-xrxg-rjqm-5pr4",
  "modified": "2026-08-17T06:33:27Z",
  "published": "2026-08-15T06:32:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72397"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5bd0d47640395f8a8c34446b62d1781b88869dfa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/828cd614e2af053ca5e1d6da767bbd8a1b5cabfb"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

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

Vulnerability from cvelistv5 – Published: 2026-08-15 05:56 – Updated: 2026-08-17 05:43

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

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/5bd0d47640395f8a8…
https://git.kernel.org/stable/c/828cd614e2af053ca…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 068c227056b9223fea1a759e08db2558d5cbb5ad , < 5bd0d47640395f8a8c34446b62d1781b88869dfa (git) Affected: 068c227056b9223fea1a759e08db2558d5cbb5ad , < 828cd614e2af053ca5e1d6da767bbd8a1b5cabfb (git)
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": [
            {
              "lessThan": "5bd0d47640395f8a8c34446b62d1781b88869dfa",
              "status": "affected",
              "version": "068c227056b9223fea1a759e08db2558d5cbb5ad",
              "versionType": "git"
            },
            {
              "lessThan": "828cd614e2af053ca5e1d6da767bbd8a1b5cabfb",
              "status": "affected",
              "version": "068c227056b9223fea1a759e08db2558d5cbb5ad",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "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": [
            {
              "status": "affected",
              "version": "4.3"
            },
            {
              "lessThan": "4.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "4.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "4.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "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()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "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"
}

Sightings

Author	Source	Type	Date	Other

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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GHSA-XRXG-RJQM-5PR4

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

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Nomenclature