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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
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
Which versions are affected by CVE-2026-10679?
It affects 1 product.
Products include 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.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-10679 being exploited?
There is no known exploitation of CVE-2026-10679 in the wild and no public exploit code.
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Sources
Also known as GHSA-3qcm-qwh2-v4hq.