CVE-2026-93277 RDMA/bnxt_re: Validate udata before executing commands
A use-after-free vulnerability in the Linux kernel RDMA driver allows local attackers to execute arbitrary code or escalate privileges due to improper udata validation during resource teardown.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93277?
CVE-2026-93277 is a high-severity use after free vulnerability in Linux, published on 24 Sep 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/bnxt_re: Validate udata before executing commands
The destroy callbacks currently zero the udata output after tearing down driver resources. If the userspace access fails, uverbs preserves the uobject and allows the destroy callback to run again, even though the driver resource has already been freed.
Call ib_no_udata_io() before teardown so udata failures are detected while the resource is still intact, then return success after teardown completes.
As part of this change, move ib_respond_empty_udata() to the start of the create and modify flows. While this is not strictly required for general create flows, as the core layer unwinds uobjects on failure, it is necessary for create AH. In _rdma_create_ah(), the HW object is otherwise leaked.
Which versions are affected by CVE-2026-93277?
How do I fix CVE-2026-93277?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-93277 being exploited?
There is no known exploitation of CVE-2026-93277 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-93277, GHSA-4gwr-wcr3-5gpm, UBUNTU-CVE-2026-93277.