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CVE-2026-29649 Detail

Description

NEMU contains an implementation flaw in its RISC-V Hypervisor CSR handling where henvcfg[7:4] (CBIE/CBCFE/CBZE-related fields) is incorrectly masked/updated based on menvcfg[7:4], so a machine-mode write to menvcfg can implicitly modify the hypervisor's environment configuration. This can lead to incorrect enforcement of virtualization configuration and may cause unexpected traps or denial of service when executing cache-block management instructions in virtualized contexts (V=1).


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://docs.riscv.org/reference/isa/priv/hypervisor.html MITRE
https://docs.riscv.org/reference/isa/priv/machine.html MITRE
https://github.com/OpenXiangShan/NEMU/issues/681 MITRE
https://github.com/OpenXiangShan/NEMU/pull/689 MITRE

Weakness Enumeration

CWE-ID CWE Name Source
CWE-693 Protection Mechanism Failure CISA-ADP  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-29649
NVD Published Date:
04/20/2026
NVD Last Modified:
04/21/2026
Source:
MITRE