CVE-2026-29643 Denial of service in n/a
A local attacker can cause a denial of service and inconsistent state in the XiangShan RISC-V processor by triggering improper exception handling in the CSR subsystem.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-29643?
CVE-2026-29643 is a high-severity denial of service vulnerability in n/a, published on 20 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
XiangShan (Open-source high-performance RISC-V processor) commit edb1dfaf7d290ae99724594507dc46c2c2125384 (2024-11-28) contains an improper exceptional-condition handling flaw in its CSR subsystem (NewCSR). On affected versions, certain sequences of CSR operations targeting non-existent/custom CSR addresses may trigger an illegal-instruction exception but fail to reliably transfer control to the configured trap handler (mtvec), causing control-flow disruption and potentially leaving the core in a hung or unrecoverable state. This can be exploited by a local attacker able to execute code on the processor to cause a denial of service and potentially inconsistent architectural state.
Weakness: CWE-703
Which versions are affected by CVE-2026-29643?
How do I fix CVE-2026-29643?
No fix has been published for CVE-2026-29643 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-29643 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-29643 exists.
Sources
Also known as GHSA-6pg9-3wf4-7w8v.