CVE-2026-53079 net_sched: fix skb memory leak in deferred qdisc drops

What is CVE-2026-53079?

CVE-2026-53079 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 Jun 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_sched: fix skb memory leak in deferred qdisc drops

When the network stack cleans up the deferred list via qdisc_run_end(), it operates on the root qdisc. If the root qdisc do not implement the TCQ_F_DEQUEUE_DROPS flag the packets queue to free are never freed and gets stranded on the child's local to_free list.

Fix this by making qdisc_dequeue_drop() aware of the root qdisc. It fetches the root qdisc and check for the TCQ_F_DEQUEUE_DROPS flag. If the flag is present, the packet is appended directly to the root's to_free list. Otherwise, drop it directly as it was done before the optimization was implemented.

Weakness: CWE-401

Which versions are affected by CVE-2026-53079?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-53079?

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-2026-53079 being exploited?

There is no known exploitation of CVE-2026-53079 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-53079, GHSA-8w4c-rp37-3wmc, UBUNTU-CVE-2026-53079.