CVE-2026-29646
Received Received - Intake
Privilege Escalation via CSR Write Flaw in OpenXiangShan NEMU

Publication date: 2026-04-20

Last updated on: 2026-04-21

Assigner: MITRE

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.
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Meta Information
Published
2026-04-20
Last Modified
2026-04-21
Generated
2026-05-07
AI Q&A
2026-04-21
EPSS Evaluated
2026-05-05
NVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
openxiangshan nemu to 55295c4 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-267 A particular privilege, role, capability, or right can be used to perform unsafe actions that were not intended, even when it is assigned to the correct entity.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in OpenXiangShan NEMU versions prior to commit 55295c4 when running with the RVH (Hypervisor extension) enabled. Specifically, a VS-mode guest's write to the supervisor interrupt-enable CSR (sie) may be handled incorrectly, which can improperly influence the machine-level interrupt enable state (mie).

This flaw breaks the expected privilege and virtualization isolation, meaning that the guest operating system running in virtual supervisor mode can affect machine-level interrupt settings that it should not have access to.


How can this vulnerability impact me? :

The vulnerability can lead to denial of service or privilege-boundary violations in environments that rely on NEMU for correct interrupt virtualization.

Because the guest can improperly influence machine-level interrupt enable state, it may disrupt normal system operation or escalate privileges beyond intended boundaries.


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