# CVE-2026-10679

## Summary

- **CVE ID:** CVE-2026-10679
- **Severity:** LOW
- **CVSS Score:** 3.3 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L)
- **CWE:** CWE-369
- **Published:** Jul 21, 2026
- **Last Modified:** Jul 24, 2026

## 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.

## Affected Products

- zephyrproject — zephyr (1.8.0)

## References

- [CNA](https://github.com/zephyrproject-rtos/zephyr/commit/65935885622b0e4a5dbe5b82504c30097eb75ce0)
- [CNA](https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3qcm-qwh2-v4hq)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.13%
- **EPSS Percentile:** 3.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._