Vulnerability-Lookup

GHSA-W4GM-VHRH-5H95

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) Fix passing events to regulator core

Sashiko reports:

Commit 754bd2b4a084 ("hwmon: (pmbus/core) Protect regulator operations with mutex") introduced a worker to batch regulator events over time using atomic_or(). The delayed worker then passes the combined bitmask unmodified to regulator_notifier_call_chain().

The core regulator subsystem's regulator_handle_critical() function evaluates the event parameter using a strict switch statement. If multiple distinct faults occur before the worker runs (e.g., REGULATOR_EVENT_UNDER_VOLTAGE | REGULATOR_EVENT_OVER_CURRENT), the combined bitmask fails to match any case. This leaves the reason as NULL and completely bypasses the critical hw_protection_trigger().

Fix the problem by passing events bit by bit to the regulator event handler.

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-2026-72395"
  ],
  "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) Fix passing events to regulator core\n\nSashiko reports:\n\nCommit 754bd2b4a084 (\"hwmon: (pmbus/core) Protect regulator operations with\nmutex\") introduced a worker to batch regulator events over time using\natomic_or(). The delayed worker then passes the combined bitmask unmodified\nto regulator_notifier_call_chain().\n\nThe core regulator subsystem\u0027s regulator_handle_critical() function\nevaluates the event parameter using a strict switch statement. If\nmultiple distinct faults occur before the worker runs (e.g.,\nREGULATOR_EVENT_UNDER_VOLTAGE | REGULATOR_EVENT_OVER_CURRENT), the combined\nbitmask fails to match any case. This leaves the reason as NULL and\ncompletely bypasses the critical hw_protection_trigger().\n\nFix the problem by passing events bit by bit to the regulator event\nhandler.",
  "id": "GHSA-w4gm-vhrh-5h95",
  "modified": "2026-08-17T06:33:27Z",
  "published": "2026-08-15T06:32:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72395"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2106bf4056858fcce3624e0c51f6fee4d41d3f2f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/489291b6b56978cc50d34e8e13f9636ea296ba8a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/48fe43666950efefb7ac5fbdc012c1b3604096bf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9ef7dacd44216bf5ea05c8aef49eba4d145f4047"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b0ff6b6ae9c5183ef701ece7016698bde5a5bfba"
    }
  ],
  "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-2026-72395 (GCVE-0-2026-72395)

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

Title

hwmon: (pmbus) Fix passing events to regulator core

Summary

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus) Fix passing events to regulator core Sashiko reports: Commit 754bd2b4a084 ("hwmon: (pmbus/core) Protect regulator operations with mutex") introduced a worker to batch regulator events over time using atomic_or(). The delayed worker then passes the combined bitmask unmodified to regulator_notifier_call_chain(). The core regulator subsystem's regulator_handle_critical() function evaluates the event parameter using a strict switch statement. If multiple distinct faults occur before the worker runs (e.g., REGULATOR_EVENT_UNDER_VOLTAGE | REGULATOR_EVENT_OVER_CURRENT), the combined bitmask fails to match any case. This leaves the reason as NULL and completely bypasses the critical hw_protection_trigger(). Fix the problem by passing events bit by bit to the regulator event handler.

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

5 references

URL	Tags
https://git.kernel.org/stable/c/2106bf4056858fcce…
https://git.kernel.org/stable/c/48fe43666950efefb…
https://git.kernel.org/stable/c/489291b6b56978cc5…
https://git.kernel.org/stable/c/b0ff6b6ae9c5183ef…
https://git.kernel.org/stable/c/9ef7dacd44216bf5e…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b26849cffaa7c43355b82e9bef3725e786973a1a , < 2106bf4056858fcce3624e0c51f6fee4d41d3f2f (git) Affected: acf04e2863132f6d9222f71f3a76fb9782cbe061 , < 48fe43666950efefb7ac5fbdc012c1b3604096bf (git) Affected: 4e9d723d9f198b86f6882a84c501ba1f39e8d055 , < 489291b6b56978cc50d34e8e13f9636ea296ba8a (git) Affected: 754bd2b4a084b90b5e7b630e1f423061a9b9b761 , < b0ff6b6ae9c5183ef701ece7016698bde5a5bfba (git) Affected: 754bd2b4a084b90b5e7b630e1f423061a9b9b761 , < 9ef7dacd44216bf5ea05c8aef49eba4d145f4047 (git) Affected: 2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07 (git) Affected: 6.6.143 , < 6.6.145 (semver) Affected: 6.12.92 , < 6.12.97 (semver) Affected: 6.18.21 , < 6.18.40 (semver) Affected: 6.19.11 , < 6.20 (semver)
Linux	Linux	Affected: 7.0 Unaffected: 0 , < 7.0 (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (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": "2106bf4056858fcce3624e0c51f6fee4d41d3f2f",
              "status": "affected",
              "version": "b26849cffaa7c43355b82e9bef3725e786973a1a",
              "versionType": "git"
            },
            {
              "lessThan": "48fe43666950efefb7ac5fbdc012c1b3604096bf",
              "status": "affected",
              "version": "acf04e2863132f6d9222f71f3a76fb9782cbe061",
              "versionType": "git"
            },
            {
              "lessThan": "489291b6b56978cc50d34e8e13f9636ea296ba8a",
              "status": "affected",
              "version": "4e9d723d9f198b86f6882a84c501ba1f39e8d055",
              "versionType": "git"
            },
            {
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "754bd2b4a084b90b5e7b630e1f423061a9b9b761",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "6.6.143",
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              "status": "affected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
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              "status": "affected",
              "version": "6.18.21",
              "versionType": "semver"
            },
            {
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              "status": "affected",
              "version": "6.19.11",
              "versionType": "semver"
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          "product": "Linux",
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            "drivers/hwmon/pmbus/pmbus_core.c"
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "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": [
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              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
                  "versionStartIncluding": "6.6.143",
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                },
                {
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                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "6.12.92",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                {
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                  "versionStartIncluding": "6.19.11",
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                }
              ],
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus) Fix passing events to regulator core\n\nSashiko reports:\n\nCommit 754bd2b4a084 (\"hwmon: (pmbus/core) Protect regulator operations with\nmutex\") introduced a worker to batch regulator events over time using\natomic_or(). The delayed worker then passes the combined bitmask unmodified\nto regulator_notifier_call_chain().\n\nThe core regulator subsystem\u0027s regulator_handle_critical() function\nevaluates the event parameter using a strict switch statement. If\nmultiple distinct faults occur before the worker runs (e.g.,\nREGULATOR_EVENT_UNDER_VOLTAGE | REGULATOR_EVENT_OVER_CURRENT), the combined\nbitmask fails to match any case. This leaves the reason as NULL and\ncompletely bypasses the critical hw_protection_trigger().\n\nFix the problem by passing events bit by bit to the regulator event\nhandler."
        }
      ],
      "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 flaw is only reachable through the PMBus SMBALERT threaded IRQ handler (pmbus_fault_handler) that reads hardware fault status over I2C; there is no network, adjacent-radio, or direct physical-device API path, but local actors on PMBus-equipped servers, routers, and embedded boards can induce multi-fault conditions.\nAC:L - _pmbus_get_flags() ORs multiple REGULATOR_EVENT_* bits from a single STATUS read, and pmbus_regulator_notify() further batches concurrent IRQs via atomic_or() before the worker runs, so combined masks like UNDER_VOLTAGE|OVER_CURRENT are produced deterministically without races or layout dependencies the attacker cannot influence.\nPR:L - Triggering the IRQ requires causing real PMBus regulator fault bits (e.g., over-current plus under-voltage during supply stress), which an unprivileged local user can induce through heavy workload and power instability on affected platforms; CAP_NET_ADMIN/user-namespace tricks are not needed and no init-namespace root capability is required.\nUI:N - Once fault conditions are present the SMBALERT IRQ and workqueue fire automatically through pmbus_fault_handler and pmbus_regulator_notify_worker; no separate victim action such as mounting media, plugging hardware, or approving a prompt is required.\nS:U - The impact is bypassing kernel hw_protection_trigger() orderly shutdown/reboot for system-critical PMBus regulators on the same host; it does not cross VM, IOMMU, or sandbox security boundaries and is not a guest-to-host escape.\nC:N - This is a notifier bit-mask logic error that leaves regulator_handle_critical() with a NULL reason; there is no kernel memory corruption, use-after-free, or out-of-bounds access that could disclose pointers or arbitrary memory.\nI:H - When multiple distinct fault events are combined, hw_protection_trigger() is completely skipped for system-critical regulators, defeating the kernel\u0027s mandatory emergency shutdown policy and allowing continued operation under simultaneous critical under-voltage/over-current/fail conditions that can corrupt power hardware.\nA:H - Bypassing hw_protection_trigger() during simultaneous critical PMBus regulator faults prevents the intended emergency orderly_poweroff/reboot, leaving telecom, data-center, and embedded systems running under dangerous rail conditions that can cause hardware failure, forced resets, and sustained denial of service."
            }
          ]
        }
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      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:43:38.599Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
          "url": "https://git.kernel.org/stable/c/b0ff6b6ae9c5183ef701ece7016698bde5a5bfba"
        },
        {
          "url": "https://git.kernel.org/stable/c/9ef7dacd44216bf5ea05c8aef49eba4d145f4047"
        }
      ],
      "title": "hwmon: (pmbus) Fix passing events to regulator core",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72395",
    "datePublished": "2026-08-15T05:56:22.400Z",
    "dateReserved": "2026-08-09T03:40:39.924Z",
    "dateUpdated": "2026-08-17T05:43:38.599Z",
    "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-W4GM-VHRH-5H95

CVE-2026-72395 (GCVE-0-2026-72395)

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Sightings

Nomenclature