Vulnerability in N/a
CVE-2026-29644
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.001 (3.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000
Weakness classification (CWE)
References
- github.com/OpenXiangShan/XiangShan/issues/3959
- docs.riscv.org/reference/isa/priv/priv-csrs.html
- github.com/OpenXiangShan/XiangShan/commit/2b1f9796aa98597e5eeac32e5bb1418496987…
- github.com/OpenXiangShan/XiangShan/commit/edb1dfaf7d290ae99724594507dc46c2c2125…
- xiangshan-doc-test.readthedocs.io/next/memory/mmu/pmp_pma/
Frequently asked questions
- What is CVE-2026-29644?
- CVE-2026-29644 is a medium-severity vulnerability in N/a, classified under Improper Access Control. CVSS score: 5.3/10. Published 2026-04-21.
- How severe is CVE-2026-29644?
- Medium severity. CVSS v3 base score is 5.3 out of 10.