Privilege escalation in N/a
CVE-2026-29646
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (51.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003
Weakness classification (CWE)
References
- docs.riscv.org/reference/isa/priv/machine.html
- github.com/OpenXiangShan/NEMU/issues/951
- github.com/OpenXiangShan/NEMU/pull/938
- github.com/OpenXiangShan/NEMU/pull/938/commits/55295c46580456d8d5a9d5736e1fda92…
- docs.riscv.org/reference/isa/unpriv/zicsr.html
- docs.riscv.org/reference/isa/priv/supervisor.html
- docs.riscv.org/reference/isa/priv/hypervisor.html
Frequently asked questions
- What is CVE-2026-29646?
- CVE-2026-29646 is a critical-severity vulnerability in N/a, classified under Privilege Defined With Unsafe Actions. CVSS score: 9.8/10. Published 2026-04-20.
- How severe is CVE-2026-29646?
- Critical severity. CVSS v3 base score is 9.8 out of 10.