CVE-2026-29644

CVE-2026-29644 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-284.

Key facts

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-29644?
CVE-2026-29644 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-29644 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-29644?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-29644 have an EU (EUVD) identifier?
Yes. CVE-2026-29644 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24131.
When was CVE-2026-29644 published?
CVE-2026-29644 was published on 2026-04-21 and last updated on 2026-06-17.

References

Other CWE-284 (Improper Access Control) vulnerabilities

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