CVE-2026-74386 nvmet-tcp: fix page fragment cache leak in error path

Not scored Published 15 Aug 2026 Updated 21 Oct 2026

A memory leak in the Linux kernel's nvmet-tcp module allows remote attackers to cause denial of service by repeatedly opening and closing connections.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-74386?

CVE-2026-74386 is a denial of service vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

nvmet-tcp: fix page fragment cache leak in error path

In nvmet_tcp_alloc_queue(), when a connection is closed during the allocation process (e.g., nvmet_tcp_set_queue_sock() returns -ENOTCONN), the error handling jumps to out_destroy_sq and then to out_ida_remove without draining the page fragment cache.

Although nvmet_tcp_free_cmd() is called in some error paths to release individual page fragments, the underlying page cache reference held by queue->pf_cache is never released. The first allocation using pf_cache is the call to nvmet_tcp_alloc_cmd() for queue->connect, which happens after ida_alloc() returns successfully. This results in a page leak each time a connection fails during allocation, which could lead to memory exhaustion over time if connections are repeatedly opened and closed.

Fix this by calling page_frag_cache_drain() before freeing the queue structure in the out_ida_remove label.

Which versions are affected by CVE-2026-74386?

How do I fix CVE-2026-74386?

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-2026-74386 being exploited?

There is no known exploitation of CVE-2026-74386 in the wild and no public exploit code.

Sources

Also known as AZL-96468, BELL-CVE-2026-74386, DEBIAN-CVE-2026-74386, GHSA-3685-2pvg-g2mr, UBUNTU-CVE-2026-74386.