# CVE-2026-72395: hwmon: (pmbus) Fix passing events to regulator core

> A logic error in the Linux kernel PMBus driver bypasses critical hardware protection triggers when multiple regulator faults occur simultaneously.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-72395, DEBIAN-CVE-2026-72395, GHSA-w4gm-vhrh-5h95, UBUNTU-CVE-2026-72395

## What is CVE-2026-72395?

CVE-2026-72395 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

## Which versions are affected by CVE-2026-72395?


## How do I fix CVE-2026-72395?

Apply the vendor's patch.

## Is CVE-2026-72395 being exploited?

There is no known exploitation of CVE-2026-72395 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72395 and fix it if it is affected.

What it is: CVE-2026-72395 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72395 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-72395/ (Markdown: https://insights.sbomify.com/CVE-2026-72395/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72395
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72395
- OSV: https://osv.dev/vulnerability/CVE-2026-72395

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72395/
Summaries are generated and may contain mistakes; the official description above is the record.