# CVE-2026-74547: hwmon: (adt7470) Fix busy-loop and I2C flooding in update thread

> A local attacker with sysfs write access can cause a CPU busy-loop and I2C bus flooding in the adt7470 hardware monitoring driver by setting specific parameters to zero.

- **Severity:** Not scored
- **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:** 19 Aug 2026
- **Also known as:** AZL-96120, BELL-CVE-2026-74547, DEBIAN-CVE-2026-74547, GHSA-5cx6-pvh7-gm4r, UBUNTU-CVE-2026-74547

## What is CVE-2026-74547?

CVE-2026-74547 is a denial of service 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: (adt7470) Fix busy-loop and I2C flooding in update thread

When userspace configures 'auto_update_interval' to 0 via sysfs, the
background kthread executes schedule_timeout_interruptible(0), which
returns immediately.

If 'num_temp_sensors' is concurrently or previously set to 0, the
msleep_interruptible() delay inside adt7470_read_temperatures() also
becomes 0. This combination forces the background thread into a tight,
unbounded busy-loop, hogging the CPU and flooding the I2C bus with a
continuous stream of transactions.

Fix this vulnerability by raising the lower limit of the clamp_val in
auto_update_interval_store() from 0 to 500 milliseconds. This guarantees
a reasonable minimum sleep window between sensor updates, protecting the
system from intentional or accidental I2C bus denial of service.

## Which versions are affected by CVE-2026-74547?


## How do I fix CVE-2026-74547?

Apply the vendor's patch.

## Is CVE-2026-74547 being exploited?

There is no known exploitation of CVE-2026-74547 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74547 and fix it if it is affected.

What it is: CVE-2026-74547 is a denial of service 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-2026-74547 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-2026-74547/ (Markdown: https://insights.sbomify.com/CVE-2026-74547/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74547
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74547
- OSV: https://osv.dev/vulnerability/CVE-2026-74547

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74547/
Summaries are generated and may contain mistakes; the official description above is the record.