CVE-2026-72308 mlxsw: fix refcount leak in mlxsw_sp_port_lag_join()
A refcount leak in the mlxsw network driver allows local attackers to cause a denial of service by exhausting kernel resources.
- 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-2026-72308?
CVE-2026-72308 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:
mlxsw: fix refcount leak in mlxsw_sp_port_lag_join()
When mlxsw_sp_port_lag_index_get() fails, mlxsw_sp_port_lag_join() returns an error without releasing the lag reference obtained by the earlier mlxsw_sp_lag_get(). All other error paths in the function jump to the cleanup label that ends with mlxsw_sp_lag_put(), so this is a single missed release.
Fix the leak by replacing the bare 'return err' with a goto to the existing error cleanup label, which will drop the reference safely.
Which versions are affected by CVE-2026-72308?
How do I fix CVE-2026-72308?
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-2026-72308 being exploited?
There is no known exploitation of CVE-2026-72308 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72308, DEBIAN-CVE-2026-72308, GHSA-62qp-mh75-mrwp, UBUNTU-CVE-2026-72308.