NEMU up to 2025.12.r1 RISC-V Vector Decoder funct3 denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.4$0-$5k8.39

Summaryinfo

A vulnerability labeled as problematic has been found in NEMU up to 2025.12.r1. The impacted element is an unknown function of the component RISC-V Vector Decoder. Executing a manipulation of the argument funct3 can lead to denial of service. The identification of this vulnerability is CVE-2026-29645. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in NEMU up to 2025.12.r1. This vulnerability affects an unknown part of the component RISC-V Vector Decoder. The manipulation of the argument funct3 with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability was named CVE-2026-29645 since 03/04/2026. Technical details are known, but there is no available exploit.

Upgrading to version 2025.12.r2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-23937). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: NEMU 2025.12.r2

Timelineinfo

03/04/2026 CVE reserved
04/20/2026 +46 days Advisory disclosed
04/20/2026 +0 days VulDB entry created
04/20/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-29645 (🔒)
GCVE (CVE): GCVE-0-2026-29645
GCVE (VulDB): GCVE-100-358354
EUVD: 🔒

Entryinfo

Created: 04/20/2026 21:50
Updated: 04/20/2026 23:33
Changes: 04/20/2026 21:50 (55), 04/20/2026 23:33 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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