CVE-2023-53733 net: sched: cls_u32: Undo tcf_bind_filter if u32_replace_hw_knode

High 7.8 Published 24 Oct 2025 Updated 15 Oct 2026

A missing undo operation in the Linux kernel's traffic control scheduler can lead to resource leaks or instability when hardware offload fails.

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-2023-53733?

CVE-2023-53733 is a high-severity vulnerability in Linux, published on 24 Oct 2025. 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: sched: cls_u32: Undo tcf_bind_filter if u32_replace_hw_knode

When u32_replace_hw_knode fails, we need to undo the tcf_bind_filter operation done at u32_set_parms.

Which versions are affected by CVE-2023-53733?

How do I fix CVE-2023-53733?

Apply the vendor's patch.

Is CVE-2023-53733 being exploited?

There is no known exploitation of CVE-2023-53733 in the wild and no public exploit code.

Sources

Also known as BELL-CVE-2023-53733, DEBIAN-CVE-2023-53733, GHSA-x89v-x9wm-242x, ROOT-OS-DEBIAN-11-CVE-2023-53733, ROOT-OS-UBUNTU-2204-CVE-2023-53733, UBUNTU-CVE-2023-53733.