XiangShan (open-source high-performance RISC-V processor) commit edb1dfaf7d290ae99724594507dc46c2c2125384 (2024-11-28) has improper gating of its distributed CSR write-enable path, allowing illegal CSR write attempts to alter custom PMA (Physical Memory Attribute) CSR state. Though the RISC-V privileged specification requires an illegal-instruction exception for non-existent/illegal CSR accesses, affected XiangShan versions may still propagate such writes to replicated PMA configuration state. Local attackers able to execute code on the core (privilege context depends on system integration) can exploit this to tamper with memory-attribute enforcement, potentially leading to privilege escalation, information disclosure, or denial of service depending on how PMA enforces platform security and isolation boundaries.
History

Wed, 22 Apr 2026 07:45:00 +0000

Type Values Removed Values Added
Title Improper CSR Write Gating Enables Unauthorized PMA Modification in XiangShan RISC‑V Processor

Wed, 22 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-284
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 21 Apr 2026 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Openxiangshan
Openxiangshan xiangshan
Vendors & Products Openxiangshan
Openxiangshan xiangshan

Tue, 21 Apr 2026 14:30:00 +0000

Type Values Removed Values Added
Description XiangShan (open-source high-performance RISC-V processor) commit edb1dfaf7d290ae99724594507dc46c2c2125384 (2024-11-28) has improper gating of its distributed CSR write-enable path, allowing illegal CSR write attempts to alter custom PMA (Physical Memory Attribute) CSR state. Though the RISC-V privileged specification requires an illegal-instruction exception for non-existent/illegal CSR accesses, affected XiangShan versions may still propagate such writes to replicated PMA configuration state. Local attackers able to execute code on the core (privilege context depends on system integration) can exploit this to tamper with memory-attribute enforcement, potentially leading to privilege escalation, information disclosure, or denial of service depending on how PMA enforces platform security and isolation boundaries.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2026-04-21T00:00:00.000Z

Updated: 2026-04-21T17:59:06.506Z

Reserved: 2026-03-04T00:00:00.000Z

Link: CVE-2026-29644

cve-icon Vulnrichment

Updated: 2026-04-21T17:51:18.870Z

cve-icon NVD

Status : Deferred

Published: 2026-04-21T15:16:36.090

Modified: 2026-04-21T18:16:34.467

Link: CVE-2026-29644

cve-icon Redhat

No data.