# CVE-2026-10679: Divide-by-zero in DesignWare SPI driver reachable from spi_transceive syscall (local DoS)

> A local attacker with SPI access can cause a kernel crash by passing zero frequency to the DesignWare SPI driver, requiring userspace support enabled.

- **Severity:** Low 3.3 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **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-3qcm-qwh2-v4hq

## What is CVE-2026-10679?

CVE-2026-10679 is a low-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 DesignWare SPI driver (drivers/spi/spi_dw.c) computed the SPI BAUDR clock divider as info->clock_frequency / config->frequency without validating config->frequency.

spi_transceive is a Zephyr __syscall and its verify handler (drivers/spi/spi_handlers.c) copies the caller-supplied spi_config from userspace without checking the frequency field, so a userspace thread that has been granted access to a DesignWare SPI device kernel object can pass frequency = 0 and trigger an unsigned integer divide-by-zero in spi_dw_configure().

On Cortex-M Mainline (SCB->CCR.DIV_0_TRP is set in z_arm_fault_init()) and on ARC (a dedicated __ev_div_zero vector) this raises a CPU exception, resulting in a kernel fault and local denial of service.

The fix rejects zero frequency and frequencies above clock_frequency / 2 (the DesignWare SSI databook minimum SCKDIV of 2) with -EINVAL. The defect affects all Zephyr releases up to and including v4.4.0; exploitation requires CONFIG_USERSPACE=y and an unprivileged thread already granted SPI driver permission. There is no memory-corruption or information-disclosure impact.

Weakness: CWE-369 (Divide By Zero)

## Which versions are affected by CVE-2026-10679?

It affects 1 product.


Products: Zephyrproject Zephyr.

## How do I fix CVE-2026-10679?

No fix has been published for CVE-2026-10679 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-10679 being exploited?

There is no known exploitation of CVE-2026-10679 in the wild and no public exploit code.

## Other vulnerabilities in Zephyrproject Zephyr

- [CVE-2026-5067](https://insights.sbomify.com/CVE-2026-5067/): Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key (critical 9.8)
- [CVE-2022-3806](https://insights.sbomify.com/CVE-2022-3806/): Bluetooth HCI Error Handling Double Free (critical 9.8)
- [CVE-2017-14199](https://insights.sbomify.com/CVE-2017-14199/): Memory corruption in getaddrinfo (critical 9.8)
- [CVE-2018-1000800](https://insights.sbomify.com/CVE-2018-1000800/): Null dereference in n/a (critical 9.8)
- [CVE-2021-3329](https://insights.sbomify.com/CVE-2021-3329/): DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10679 and fix it if it is affected.

What it is: CVE-2026-10679 is a low-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-2026-10679 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-2026-10679/ (Markdown: https://insights.sbomify.com/CVE-2026-10679/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10679
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10679
- OSV: https://osv.dev/vulnerability/CVE-2026-10679

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-10679/
Summaries are generated and may contain mistakes; the official description above is the record.