CVE-2026-52984 net/sched: netem: fix queue limit check to include reordered packets

What is CVE-2026-52984?

CVE-2026-52984 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: netem: fix queue limit check to include reordered packets

The queue limit check in netem_enqueue() uses q->t_len which only counts packets in the internal tfifo. Packets placed in sch->q by the reorder path (__qdisc_enqueue_head) are not counted, allowing the total queue occupancy to exceed sch->limit under reordering.

Include sch->q.qlen in the limit check.

Which versions are affected by CVE-2026-52984?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-52984?

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-2026-52984 being exploited?

There is no known exploitation of CVE-2026-52984 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 BELL-CVE-2026-52984, DEBIAN-CVE-2026-52984, GHSA-29w2-r4qv-vcrw, ROOT-OS-UBUNTU-2204-CVE-2026-52984, ROOT-OS-UBUNTU-2404-CVE-2026-52984, UBUNTU-CVE-2026-52984.