by Kastro
Paper/Archive/CVE-2026-29649

CVE-2026-29649

mitre — NEMU contains an implementation flaw in its RISC-V Hypervisor CSR handling where henvcfg[7:4] (CBIE/CBCFE/CBZE-related fields) is incorre…

EPSS 0.4%CVSS 9.8
critical.is priorityof 100
37
CVSS 9.8 (ADP)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 39.0.390 × 207.8No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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).

Affected

ProductAffectedFixed inSource
n/an/a–CNA

Scores by source

CISA ADP9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/OpenXiangShan/NEMU/issues/681refgithub.com/OpenXiangShan/NEMU/pull/689refdocs.riscv.org/reference/isa/priv/machine.htmlrefdocs.riscv.org/reference/isa/priv/hypervisor.html