CVE-2026-10674: dos in zephyrproject zephyr
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.
AI Analysis
Technical Summary
The NXP LPUART serial driver in Zephyr, when configured with CONFIG_UART_USE_RUNTIME_CONFIGURE, calls LPUART_Deinit() at the start of mcux_lpuart_configure(), disabling the peripheral clocks before validating the requested UART configuration. If the configuration is unsupported, the clock remains disabled, causing any further UART register access to trigger a hard fault and crash the system. The uart_configure() syscall does not validate the configuration beyond checking memory readability, allowing an unprivileged userspace thread to trigger this fault deterministically, causing a system-wide denial of service. This vulnerability was introduced in Zephyr v2.5.0 and fixed by removing the LPUART_Deinit() call and only disabling the transmitter/receiver while leaving the clock running.
Potential Impact
An unprivileged userspace thread with access to an LPUART device can cause a persistent system-wide denial of service by triggering a hard fault through an unsupported UART configuration request. This results in a crash of the entire system. There is no impact on confidentiality or integrity, only availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The fix involves removing the call to LPUART_Deinit() and instead disabling only the transmitter and receiver while keeping the clock enabled. Until patched, restrict unprivileged userspace access to LPUART devices to prevent exploitation.
CVE-2026-10674: dos in zephyrproject zephyr
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.
CVSS v3.1
Score 5.5medium
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The NXP LPUART serial driver in Zephyr, when configured with CONFIG_UART_USE_RUNTIME_CONFIGURE, calls LPUART_Deinit() at the start of mcux_lpuart_configure(), disabling the peripheral clocks before validating the requested UART configuration. If the configuration is unsupported, the clock remains disabled, causing any further UART register access to trigger a hard fault and crash the system. The uart_configure() syscall does not validate the configuration beyond checking memory readability, allowing an unprivileged userspace thread to trigger this fault deterministically, causing a system-wide denial of service. This vulnerability was introduced in Zephyr v2.5.0 and fixed by removing the LPUART_Deinit() call and only disabling the transmitter/receiver while leaving the clock running.
Potential Impact
An unprivileged userspace thread with access to an LPUART device can cause a persistent system-wide denial of service by triggering a hard fault through an unsupported UART configuration request. This results in a crash of the entire system. There is no impact on confidentiality or integrity, only availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The fix involves removing the call to LPUART_Deinit() and instead disabling only the transmitter and receiver while keeping the clock enabled. Until patched, restrict unprivileged userspace access to LPUART devices to prevent exploitation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- zephyr
- Date Reserved
- 2026-06-02T15:26:03.742Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a5fe6ba9c2644c7f8cb00b9
Added to database: 07/21/2026, 21:38:02 UTC
Last enriched: 07/22/2026, 10:08:53 UTC
Last updated: 07/31/2026, 19:22:57 UTC
Views: 7
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