CVE-2026-29646
In OpenXiangShan NEMU vulnerability
- Published20 Apr 2026
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 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
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
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-29646 being actively exploited?
CVE-2026-29646 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.68%.
How severe is CVE-2026-29646?
CVE-2026-29646 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.68% probability of exploitation.
How do I fix CVE-2026-29646?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-29646 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.