CVE-2026-29644
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. Limited direct impact.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.3 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Weakness
- CWE-284 · Improper access control
- Record status
- Deferred
Attack profile CVSS 3.1 · 5.3
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-29644.md and follow it. Check whether this project is affected by CVE-2026-29644. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/OpenXiangShan/XiangShan/commit/2b1f9796aa98597e5eeac32e5bb1418496987ca4
- https://github.com/OpenXiangShan/XiangShan/commit/edb1dfaf7d290ae99724594507dc46c2c2125384
References
- https://docs.riscv.org/reference/isa/priv/priv-csrs.html
- https://github.com/OpenXiangShan/XiangShan/commit/2b1f9796aa98597e5eeac32e5bb1418496987ca4
- https://github.com/OpenXiangShan/XiangShan/commit/edb1dfaf7d290ae99724594507dc46c2c2125384
- https://github.com/OpenXiangShan/XiangShan/issues/3959
- https://xiangshan-doc-test.readthedocs.io/next/memory/mmu/pmp_pma/
- https://github.com/OpenXiangShan/XiangShan/issues/3959