A buffer overflow in the recvmsg function of the ls1c CAN handler allows an attacker to corrupt the stack when a CAN message is processed. The flaw, indexed as CWE-119 and CWE-121, can lead to arbitrary code execution, denial of service, or other integrity and availability compromises. The vulnerability is limited to local execution; it cannot be triggered from remote hosts without local CAN access.

RT‑Thread firmware versions up to and including 5.0.2 that include the ls1c CAN implementation in bsp/loongson/ls1cdev/libraries/ls1c_can.h are affected. Devices that expose the LS1C CAN interface to local traffic—such as embedded automotive or industrial controllers—are at risk if they run any of these vulnerable builds.

Given a CVSS score of 8.5 the issue is high severity. The EPSS score is below 1 % and the vulnerability is not yet in the CISA KEV catalog, yet a public exploit exists. Based on the description it is inferred that an attacker must have local access to the CAN controller to deliver a malicious message, but once local access is achieved the exploitation probability is realistic. For deployments where local CAN access is unrestricted, the risk of successful compromise remains significant.