# CVE-2026-72397: hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()

> Incorrect voltage encoding in the Linux kernel PMBus driver can cause hardware to receive wrong voltage commands, potentially leading to hardware damage or instability.

- **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:** 21 Oct 2026
- **Also known as:** AZL-96290, BELL-CVE-2026-72397, DEBIAN-CVE-2026-72397, GHSA-xrxg-rjqm-5pr4, UBUNTU-CVE-2026-72397

## What is CVE-2026-72397?

CVE-2026-72397 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/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.

## Which versions are affected by CVE-2026-72397?


## How do I fix CVE-2026-72397?

Apply the vendor's patch.

## Is CVE-2026-72397 being exploited?

There is no known exploitation of CVE-2026-72397 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72397 and fix it if it is affected.

What it is: CVE-2026-72397 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-2026-72397 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-2026-72397/ (Markdown: https://insights.sbomify.com/CVE-2026-72397/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72397
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72397
- OSV: https://osv.dev/vulnerability/CVE-2026-72397

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72397/
Summaries are generated and may contain mistakes; the official description above is the record.