CVE-2026-29646 json
In OpenXiangShan NEMU prior to 55295c4, when running with RVH (Hypervisor extension) enabled, a VS-mode guest write to the supervisor inter…
published 2026-04-20 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-23958
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 30%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- github.com/OpenXiangShan/NEMU#938 commit
- github.com/OpenXiangShan/NEMU#938 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 6 mo ago
Exploit prediction
0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Classification
- Weakness
-
- CWE-267 Privilege Defined With Unsafe Actions
References
- github.com /OpenXiangShan/NEMU/pull/938
- github.com /OpenXiangShan/NEMU/pull/938/commits/55295c46580456d8d5a9d5736e1fda924b8825ab
- docs.riscv.org /reference/isa/priv/machine.html
- github.com /OpenXiangShan/NEMU/issues/951
- docs.riscv.org /reference/isa/unpriv/zicsr.html
- docs.riscv.org /reference/isa/priv/supervisor.html
- docs.riscv.org /reference/isa/priv/hypervisor.html
Sources
- CVE List CVE-2026-29646
- NVD CVE-2026-29646
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