What is CVE-2026-29649?

CVE-2026-29649 is a critical-severity vulnerability in Xiangshan Nemu, classified under Protection Mechanism Failure. CVSS score: 9.8/10. Published 2026-04-20.

How severe is CVE-2026-29649?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Xiangshan Nemu

CVE-2026-29649

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 th…

EPSS: 0.004 (36.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Xiangshan Nemu
N/a — versions n/a

Weakness classification (CWE)

CWE-693 — Protection Mechanism Failure

References

cve@mitre.org (Issue Tracking)
cve@mitre.org (Patch, Issue Tracking)
cve@mitre.org (Product)
cve@mitre.org (Product)

Frequently asked questions

What is CVE-2026-29649?: CVE-2026-29649 is a critical-severity vulnerability in Xiangshan Nemu, classified under Protection Mechanism Failure. CVSS score: 9.8/10. Published 2026-04-20.
How severe is CVE-2026-29649?: Critical severity. CVSS v3 base score is 9.8 out of 10.