# CVE-2026-89462: power: supply: max17040: propagate register read errors

> An attacker with local access can read uninitialized memory values as valid battery voltage or state of charge due to ignored I2C read errors in the max17040 driver.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-100575, BELL-CVE-2026-89462, DEBIAN-CVE-2026-89462, GHSA-2jg4-h8v3-7354, UBUNTU-CVE-2026-89462

## What is CVE-2026-89462?

CVE-2026-89462 is a vulnerability in Linux, published on 11 Sep 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:

power: supply: max17040: propagate register read errors

max17040_get_vcell() and max17040_get_soc() ignore errors returned by
regmap_read().  When an I2C transfer fails, the uninitialized register
value is converted and reported to userspace as a valid voltage or state
of charge.  The polling worker can also replace the cached state of charge
with the bogus value and emit a spurious change event.

Propagate read errors through the power supply get_property callback and
keep the last valid cached state of charge when polling fails.

## Which versions are affected by CVE-2026-89462?


## How do I fix CVE-2026-89462?

Apply the vendor's patch.

## Is CVE-2026-89462 being exploited?

There is no known exploitation of CVE-2026-89462 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89462 and fix it if it is affected.

What it is: CVE-2026-89462 is a vulnerability in Linux, published on 11 Sep 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-2026-89462 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-2026-89462/ (Markdown: https://insights.sbomify.com/CVE-2026-89462/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89462
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89462
- OSV: https://osv.dev/vulnerability/CVE-2026-89462

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89462/
Summaries are generated and may contain mistakes; the official description above is the record.