CVE-2026-29649

CRITICAL EPSS 35.8%
Published Apr 20, 20262mo ago · Modified Jun 17, 20262w ago
9.8 CVSS 3.1
Critical
Find Similar
Published Apr 20, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

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).

CVSS Details

Base Score
9.8
Exploitability
3.9
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
35.8% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-693

Affected Products 1

VendorProductVersionRange
xiangshannemu*any

References 4

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

Remediation

  • github.com https://github.com/OpenXiangShan/NEMU/pull/689
    Issue TrackingPatch