The vulnerability in XiangShan's CSR subsystem arises from improper exceptional-condition handling in the NewCSR component. When executing sequences of CSR instructions targeting invalid or custom CSR addresses, the processor may trigger an illegal-instruction exception but fail to reliably invoke the configured trap handler (mtvec). This results in control-flow disruption, potentially leaving the processor core hung or in an unrecoverable state. Exploitation requires local code execution privileges and can cause denial of service and inconsistent processor state. The CVSS score is 7.1 (high severity) with attack vector local, low attack complexity, low privileges required, no user interaction, unchanged scope, no confidentiality impact, high integrity impact, and high availability impact. No patch or remediation level is currently provided by the vendor or advisory.

Successful exploitation can cause denial of service by hanging or unrecoverably disrupting the processor core's control flow. It may also lead to inconsistent architectural state, affecting integrity and availability. There is no confidentiality impact. The attack requires local code execution privileges.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is currently documented. Until a patch is available, restrict local code execution privileges to trusted users to reduce risk.