---
id: CVE-2026-75085
title: >-
  The STM32WBA IEEE 802.15.4 driver in drivers/ieee802154/ieee802154_stm32wba.c
  computed the packet length of a received frame as pkt_len = rx_frame->length -
  IEEE802154_FCS_LENGTH without first checking that the radio-reported length
  coul…
summary: >-
  The STM32WBA IEEE 802.15.4 driver in drivers/ieee802154/ieee802154_stm32wba.c
  computed the packet length of a received frame as pkt_len = rx_frame->length -
  IEEE802154_FCS_LENGTH without first checking that the radio-reported length
  coul…
severity: medium
cvss: 4.2
cvssVector: 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L'
cwe:
  - CWE-125
published: '2026-10-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T17:19:10.607'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-75085'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/commit/46f8af4f5ee472abc13b0291c44fdfe4ed879aaa
    label: vulnerabilities@zephyrproject.org
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w7pm-4r95-c9vr
    label: vulnerabilities@zephyrproject.org
tags:
  - nvd
ingestedAt: '2026-10-14T17:44:53.677Z'
---

## Overview

The STM32WBA IEEE 802.15.4 driver in drivers/ieee802154/ieee802154_stm32wba.c computed the packet length of a received frame as pkt_len = rx_frame->length - IEEE802154_FCS_LENGTH without first checking that the radio-reported length could hold an FCS. pkt_len is a uint8_t, so a reported length of 0 or 1 wrapped to 254 or 255. The only bound on the resulting value was __ASSERT_NO_MSG(pkt_len <= CONFIG_NET_BUF_DATA_SIZE), which compiles to nothing in the default production configuration (CONFIG_ASSERT=n).

The length originates in the ST link-layer receive-done metadata (p_metadata->length, stored by stm32wba_802154_receive_done()), and ultimately in the PHY header of a frame received over the air, so it is influenced by any attacker within radio range of the device. Reaching the underflow requires the vendor link layer to surface a frame shorter than the FCS with no error; the driver performed no validation of its own on that value.

When the underflow occurs, stm32wba_802154_rx_thread() calls net_pkt_write(pkt, rx_frame->psdu, pkt_len) with a length of about 254 bytes against a receive buffer that holds at most one PHY packet (IEEE802154_MAX_PHY_PACKET_SIZE, 127 bytes). This reads roughly 128 bytes past the end of the radio receive buffer and copies that adjacent memory into a network packet that is submitted to the networking stack, giving an out-of-bounds read with a potential disclosure of adjacent RAM plus needless oversized packet allocation in the RX thread.

The fix rejects a frame whose reported length is smaller than IEEE802154_FCS_LENGTH before the subtraction, and replaces the compiled-out assertion with a runtime length check that drops oversized frames — matching the runtime check already present in drivers/ieee802154/ieee802154_nrf5.c.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.