CVE-2026-29646

critical

Description

In OpenXiangShan NEMU prior to 55295c4, when running with RVH (Hypervisor extension) enabled, a VS-mode guest write to the supervisor interrupt-enable CSR (sie) may be handled incorrectly and can influence machine-level interrupt enable state (mie). This breaks privilege/virtualization isolation and can lead to denial of service or privilege-boundary violation in environments relying on NEMU for correct interrupt virtualization.

References

https://github.com/OpenXiangShan/NEMU/pull/938/commits/55295c46580456d8d5a9d5736e1fda924b8825ab

https://github.com/OpenXiangShan/NEMU/pull/938

https://github.com/OpenXiangShan/NEMU/issues/951

https://docs.riscv.org/reference/isa/unpriv/zicsr.html

https://docs.riscv.org/reference/isa/priv/supervisor.html

https://docs.riscv.org/reference/isa/priv/machine.html

https://docs.riscv.org/reference/isa/priv/hypervisor.html

Details

Source: Mitre, NVD

Published: 2026-04-20

Updated: 2026-04-21

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.0003