CVE-2026-29649

critical · 9.8

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).

9.8

CVSS

0.4%

EPSS (exploit prob.)

38th

EPSS percentile

2026-04-20

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses

CWE-693

Affected products

Vendor	Product	Affected versions
xiangshan	nemu	all versions

Check a specific version with /api/v1/cve/match.

References

https://docs.riscv.org/reference/isa/priv/hypervisor.html
https://docs.riscv.org/reference/isa/priv/machine.html
https://github.com/OpenXiangShan/NEMU/issues/681
https://github.com/OpenXiangShan/NEMU/pull/689

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-29649