CVE-2026-74389 RDMA/hns: Fix log flood after cmd_mbox failure
An attacker with local access or control over RDMA hardware can trigger a log flood leading to system crash by exploiting unratelimited error logging in the hns driver.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74389?
CVE-2026-74389 is a denial of service vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/hns: Fix log flood after cmd_mbox failure
hns_roce_cmd_mbox() is the command interface between driver and hardware. When hardware is abnormal, the unlimited error printings after hns_roce_cmd_mbox() failure will cause log flood and even system crash.
Replace ibdev_err() and ibdev_warn() with their ratelimited versions in the error handling path after hns_roce_cmd_mbox() (and its wrappers hns_roce_create_hw_ctx/hns_roce_destroy_hw_ctx) fails.
Which versions are affected by CVE-2026-74389?
How do I fix CVE-2026-74389?
Apply the vendor's patch.
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-2026-74389 being exploited?
There is no known exploitation of CVE-2026-74389 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74389, DEBIAN-CVE-2026-74389, GHSA-r243-5f6v-4cpg, UBUNTU-CVE-2026-74389.