CVE-2026-72345 net/mlx5: LAG, Fix off-by-one in single-FDB error rollback
An off-by-one error in the Linux kernel mlx5 LAG driver causes improper rollback of network rules, potentially leading to system instability or crashes.
- 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-2026-72345?
CVE-2026-72345 is a high-severity 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:
net/mlx5: LAG, Fix off-by-one in single-FDB error rollback
On failure at index i, the reverse cleanup loop in mlx5_lag_create_single_fdb() starts from i, so the failed index itself is rolled back. That can operate on uninitialized state or double-tear-down a rule the add_one path already self-rolled-back.
Start the rollback from i - 1 so only successfully-installed entries are undone.
Which versions are affected by CVE-2026-72345?
How do I fix CVE-2026-72345?
Apply the vendor's patch.
Is CVE-2026-72345 being exploited?
There is no known exploitation of CVE-2026-72345 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72345, DEBIAN-CVE-2026-72345, GHSA-2cj4-xv36-4974, UBUNTU-CVE-2026-72345.