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CVE-2026-29645 Detail

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.


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/unpriv/v-st-ext.html MITRE
https://github.com/OpenXiangShan/NEMU/commit/481de637d5fc5838356caee80a79e56a33754039 MITRE
https://github.com/OpenXiangShan/NEMU/issues/952 MITRE
https://github.com/OpenXiangShan/NEMU/pull/958 MITRE

Weakness Enumeration

CWE-ID CWE Name Source

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-29645
NVD Published Date:
04/20/2026
NVD Last Modified:
04/21/2026
Source:
MITRE