CVE-2026-29645

HIGH EPSS 41.5%
Published Apr 20, 20262mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Apr 20, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

NEMU (OpenXiangShan/NEMU) before v2025.12.r2 contains an improper instruction-validation flaw in its RISC-V Vector (RVV) decoder. The decoder does not correctly validate the funct3 field when decoding vsetvli/vsetivli/vsetvl, allowing certain invalid OP-V instruction encodings to be misinterpreted and executed as vset* configuration instructions rather than raising an illegal-instruction exception. This can be exploited by providing crafted RISC-V binaries to cause incorrect trap behavior, architectural state corruption/divergence, and potential denial of service in systems that rely on NEMU for correct execution or sandboxing.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
41.5% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-1287
CWE-131

Affected Products 1

VendorProductVersionRange
xiangshannemu2025.12any

References 4

  • docs.riscv.org https://docs.riscv.org/reference/isa/unpriv/v-st-ext.html
    Product
  • github.com https://github.com/OpenXiangShan/NEMU/commit/481de637d5fc5838356caee80a79e56a33754039
    Patch
  • github.com https://github.com/OpenXiangShan/NEMU/issues/952
    Issue Tracking
  • github.com https://github.com/OpenXiangShan/NEMU/pull/958
    Issue Tracking

Remediation

  • github.com https://github.com/OpenXiangShan/NEMU/commit/481de637d5fc5838356caee80a79e56a33754039
    Patch