A stack-based buffer overflow exists in the CAN_Receive function of the SWM341 CAN handler library shipped with RT‑Thread firmware versions up to 5.0.2. The flaw is classified as CWE‑119 and CWE‑121 and allows a local attacker who can send crafted CAN messages to overwrite stack memory, potentially leading to arbitrary code execution or a denial‑of‑service condition.

RT‑Thread firmware up to version 5.0.2 is affected. The vulnerable code resides in the SWM341_CSL/CMSIS/DeviceSupport/SWM341.h library, which implements the CAN_Receive function for SWM341 controller based devices. Any system that uses this firmware on hardware with the SWM341 CAN interface is at risk.

The CVSS score of 8.5 indicates a high severity vulnerability. The EPSS score is < 1 %, meaning that large‑scale exploitation is currently unlikely, yet an exploit has been publicly released. The vulnerability is not listed in the CISA KEV catalog. Attackers need local access to the device’s CAN bus—physical or administrative—making the risk confined to environments where the CAN interface can be manipulated directly.