Vulnerability · Published Apr 20, 2026 · Assigned by mitre
CVE-2026-29646
Critical 9.8
In plain English
A critical-severity security flaw in the affected software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities).
Official 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.
Affected products (as reported)
Weakness: CWE-267 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://docs.riscv.org/reference/isa/priv/machine.html
- https://github.com/OpenXiangShan/NEMU/issues/951
- https://github.com/OpenXiangShan/NEMU/pull/938
- https://github.com/OpenXiangShan/NEMU/pull/938/commits/55295c46580456d8d5a9d5736e1fda924b8825ab
- 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/hypervisor.html