CVE-2026-29648

Description

In OpenXiangShan NEMU, when Smstateen is enabled, clearing mstateen0.ENVCFG does not correctly restrict access to henvcfg and senvcfg. As a result, less-privileged code may read or write these CSRs without the required exception, potentially bypassing intended state-enable based isolation controls in virtualized or multi-privilege environments.

References

• https://docs.riscv.org/reference/isa/priv/smstateen.html
• https://github.com/OpenXiangShan/NEMU/issues/690
• https://github.com/OpenXiangShan/XiangShan/pull/3978