CVE-2026-72032 net/mlx5: HWS, fix matcher leak on resize target setup failure
A memory leak in the Linux kernel mlx5 HWS driver allows local attackers to cause denial of service by triggering resize failures.
- 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-2026-72032?
CVE-2026-72032 is a memory corruption 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: HWS, fix matcher leak on resize target setup failure
hws_bwc_matcher_move() allocates a replacement matcher before setting it as the resize target. If mlx5hws_matcher_resize_set_target() fails, the replacement matcher is not attached anywhere and is leaked.
Fix the leak by destroying the replacement matcher before returning from the resize-target failure path.
The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in v7.1.1.
An x86_64 allyesconfig build showed no new warnings. As we do not have a mlx5 HWS-capable device to test with, no runtime testing was able to be performed.
Which versions are affected by CVE-2026-72032?
How do I fix CVE-2026-72032?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-72032 being exploited?
There is no known exploitation of CVE-2026-72032 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72032, DEBIAN-CVE-2026-72032, GHSA-j7xx-3c7m-pgh9, UBUNTU-CVE-2026-72032.