# CVE-2026-10674: DoS (hard fault) in NXP LPUART driver: unsupported runtime UART config leaves clocks disabled

> An unprivileged user can crash the system by requesting an unsupported UART configuration, causing a hard fault due to disabled clocks.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** No
- **Published:** 21 Jul 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-mw68-r353-m3vf

## What is CVE-2026-10674?

CVE-2026-10674 is a medium-severity denial of service vulnerability in Zephyrproject Zephyr, published on 21 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The NXP LPUART serial driver (drivers/serial/uart_mcux_lpuart.c), when CONFIG_UART_USE_RUNTIME_CONFIGURE is enabled, called LPUART_Deinit() at the start of mcux_lpuart_configure(), which disables the LPUART peripheral clocks. The requested configuration is validated only afterwards (in mcux_lpuart_configure_basic), and unsupported parity/data-bit/stop-bit/flow-control values return -ENOTSUP before the clock is re-enabled.

As a result, a uart_configure() request with an unsupported configuration left the LPUART in a clock-disabled state; any subsequent access to LPUART registers (poll_out/poll_in, interrupt handling, or a later reconfigure) faults on the gated peripheral and escalates to a hard fault, crashing the system.

uart_configure() is a Zephyr syscall whose verifier (z_vrfy_uart_configure) only checks that cfg is readable user memory and forwards the caller-supplied configuration unchanged, so an unprivileged userspace thread with access to an LPUART device can deterministically trigger the fault, a persistent system-wide denial of service.

Introduced in v2.5.0 and present in all subsequent releases until this fix, which removes the LPUART_Deinit() call and instead only disables the transmitter/receiver, leaving the clock running.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2026-10674?

It affects 1 product.


Products: Zephyrproject Zephyr.

## How do I fix CVE-2026-10674?

No fix has been published for CVE-2026-10674 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-10674 being exploited?

There is no known exploitation of CVE-2026-10674 in the wild and no public exploit code.

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## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10674 and fix it if it is affected.

What it is: CVE-2026-10674 is a medium-severity denial of service vulnerability in Zephyrproject Zephyr, published on 21 Jul 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-2026-10674 in the wild and no public exploit code.

Affected product: Zephyrproject Zephyr. 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-2026-10674/ (Markdown: https://insights.sbomify.com/CVE-2026-10674/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10674
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10674
- OSV: https://osv.dev/vulnerability/CVE-2026-10674

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-10674/
Summaries are generated and may contain mistakes; the official description above is the record.