CVE-2026-29642

Privilege Escalation via Status Register Tampering on XiangShan RISC‑V Processors

Published Apr 20, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
A local attacker who can execute privileged CSR operations (or can induce firmware to do so) performs carefully crafted reads/writes to menvcfg (e.g., csrrs in M-mode). On affected XiangShan versions (commit aecf601e803bfd2371667a3fb60bfcd83c333027, 2024-11-19), these menvcfg accesses can unexpectedly set WPRI (reserved) bits in the status view (xstatus) to 1. RISC-V defines WPRI fields as "writes preserve values, reads ignore values," i.e., they must not be modified by software manipulating other fields, and menvcfg itself contains multiple WPRI fields.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Privilege Escalation via Status Register Tampering on XiangShan RISC‑V Processors
Type Values Removed Values Added
Title Privileged CSR Access Enables Corruption of Reserved Bits in XiangShan Status Register
Weaknesses CWE-682
Type Values Removed Values Added
Weaknesses CWE-1244
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

ssvc

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

Type Values Removed Values Added
First Time appeared Openxiangshan
Openxiangshan xiangshan
Vendors & Products Openxiangshan
Openxiangshan xiangshan
Type Values Removed Values Added
Title Privileged CSR Access Enables Corruption of Reserved Bits in XiangShan Status Register
Weaknesses CWE-682
Type Values Removed Values Added
Description A local attacker who can execute privileged CSR operations (or can induce firmware to do so) performs carefully crafted reads/writes to menvcfg (e.g., csrrs in M-mode). On affected XiangShan versions (commit aecf601e803bfd2371667a3fb60bfcd83c333027, 2024-11-19), these menvcfg accesses can unexpectedly set WPRI (reserved) bits in the status view (xstatus) to 1. RISC-V defines WPRI fields as "writes preserve values, reads ignore values," i.e., they must not be modified by software manipulating other fields, and menvcfg itself contains multiple WPRI fields.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Apr 21, 2026, 7:50 PM
Reserved
Mar 4, 2026, 12:00 AM
Status
Awaiting Analysis
Published
Apr 20, 2026, 9:16 PM
Modified
Jun 17, 2026, 10:29 AM