CVE-2026-29646
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.36% probability · 30th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-267
- Source
- cve@mitre.org
References
- https://docs.riscv.org/reference/isa/priv/hypervisor.html
- https://docs.riscv.org/reference/isa/priv/machine.html
- https://docs.riscv.org/reference/isa/priv/supervisor.html
- https://docs.riscv.org/reference/isa/unpriv/zicsr.html
- https://github.com/OpenXiangShan/NEMU/issues/951
- https://github.com/OpenXiangShan/NEMU/pull/938
- https://github.com/OpenXiangShan/NEMU/pull/938/commits/55295c46580456d8d5a9d5736e1fda924b8825ab
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.