OpenXiangShan NEMU RISC-V Hypervisor CSR denial of service

CVSS Meta Temp Score
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CTI Interest Score
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3.4$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in OpenXiangShan NEMU. This affects an unknown part of the component RISC-V Hypervisor CSR Handler. Executing a manipulation can lead to denial of service. This vulnerability is registered as CVE-2026-29649. No exploit is available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in OpenXiangShan NEMU (affected version not known). It has been declared as problematic. This vulnerability affects some unknown functionality of the component RISC-V Hypervisor CSR Handler. The manipulation 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 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).

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-29649 since 03/04/2026. There are neither technical details nor an exploit publicly available.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Name

Website

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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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

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: github.com

Timelineinfo

03/04/2026 CVE reserved
04/21/2026 +47 days Advisory disclosed
04/21/2026 +0 days VulDB entry created
04/21/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 681
Status: Confirmed

CVE: CVE-2026-29649 (🔒)
GCVE (CVE): GCVE-0-2026-29649
GCVE (VulDB): GCVE-100-358360

Entryinfo

Created: 04/21/2026 06:40
Changes: 04/21/2026 06:40 (55)
Complete: 🔍
Cache ID: 216::103

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