# CVE-2026-72344: net/mlx5e: TC, skip peer flow cleanup when LAG seq is unavailable

> A null pointer dereference in the Mellanox mlx5 network driver causes a kernel crash when LAG sequence numbers are unavailable.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-72344, GHSA-p5q5-g8w9-fgw6, UBUNTU-CVE-2026-72344

## What is CVE-2026-72344?

CVE-2026-72344 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/mlx5e: TC, skip peer flow cleanup when LAG seq is unavailable

mlx5_lag_get_dev_seq() will return error when the peer isn't in the LAG
or when no device is marked as master. Result bad memory access and kernel
crash[1].

Hence, skip the peer when lookup fails.

Note: In case there are peer flows, they are cleaned before LAG cleared
the master mark.

[1]
RIP: 0010:mlx5e_tc_del_fdb_peers_flow+0x3d/0x350 [mlx5_core]
Call Trace:
 <TASK>
 mlx5e_tc_clean_fdb_peer_flows+0xc1/0x130 [mlx5_core]
 mlx5_esw_offloads_unpair+0x3a/0x400 [mlx5_core]
 mlx5_esw_offloads_devcom_event+0xee/0x360 [mlx5_core]
 mlx5_devcom_send_event+0x7a/0x140 [mlx5_core]
 mlx5_esw_offloads_devcom_cleanup+0x2f/0x90 [mlx5_core]
 mlx5e_tc_esw_cleanup+0x28/0xf0 [mlx5_core]
 mlx5e_rep_tc_cleanup+0x19/0x30 [mlx5_core]
 mlx5e_cleanup_uplink_rep_tx+0x36/0x40 [mlx5_core]
 mlx5e_cleanup_rep_tx+0x55/0x60 [mlx5_core]
 mlx5e_detach_netdev+0x96/0xf0 [mlx5_core]
 mlx5e_netdev_change_profile+0x5b/0x120 [mlx5_core]
 mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core]
 mlx5e_vport_rep_unload+0xdd/0x110 [mlx5_core]
 __esw_offloads_unload_rep+0x81/0xb0 [mlx5_core]
 mlx5_eswitch_unregister_vport_reps+0x1d7/0x220 [mlx5_core]
 mlx5e_rep_remove+0x22/0x30 [mlx5_core]
 device_release_driver_internal+0x194/0x1f0
 bus_remove_device+0xe8/0x1b0
 device_del+0x159/0x3c0
 mlx5_rescan_drivers_locked+0xbc/0x2d0 [mlx5_core]
 mlx5_unregister_device+0x54/0x80 [mlx5_core]
 mlx5_uninit_one+0x73/0x130 [mlx5_core]
 remove_one+0x78/0xe0 [mlx5_core]
 pci_device_remove+0x39/0xa0

## Which versions are affected by CVE-2026-72344?


## How do I fix CVE-2026-72344?

Apply the vendor's patch.

## Is CVE-2026-72344 being exploited?

There is no known exploitation of CVE-2026-72344 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72344 and fix it if it is affected.

What it is: CVE-2026-72344 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.
Exploitation: There is no known exploitation of CVE-2026-72344 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-72344/ (Markdown: https://insights.sbomify.com/CVE-2026-72344/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72344
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72344
- OSV: https://osv.dev/vulnerability/CVE-2026-72344

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72344/
Summaries are generated and may contain mistakes; the official description above is the record.