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CVE-2026-29645
HIGH7.5
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.
CVE Details
CVSS v3.1 Score7.5
SeverityHIGH
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack VectorNETWORK
ComplexityLOW
Privileges RequiredNONE
User InteractionNONE
Published4/20/2026
Last Modified4/24/2026
Sourcenvd
Honeypot Sightings0
Affected Products
xiangshan:nemu
Weaknesses (CWE)
CWE-131CWE-1287
References
https://docs.riscv.org/reference/isa/unpriv/v-st-ext.html(cve@mitre.org)
https://github.com/OpenXiangShan/NEMU/commit/481de637d5fc5838356caee80a79e56a33754039(cve@mitre.org)
https://github.com/OpenXiangShan/NEMU/issues/952(cve@mitre.org)
https://github.com/OpenXiangShan/NEMU/pull/958(cve@mitre.org)
IOC Correlations
No correlations recorded
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