CVE-2026-43394 nfsd: Fix cred ref leak in nfsd_nl_listener_set_doit().

Medium 5.5 Published Updated

A credential reference leak in the Linux kernel NFS daemon can lead to resource exhaustion and denial of service.

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-2026-43394?

CVE-2026-43394 is a medium-severity denial of service vulnerability in Linux kernel, published on 8 May 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:

nfsd: Fix cred ref leak in nfsd_nl_listener_set_doit().

nfsd_nl_listener_set_doit() uses get_current_cred() without put_cred().

As we can see from other callers, svc_xprt_create_from_sa() does not require the extra refcount.

nfsd_nl_listener_set_doit() is always in the process context, sendmsg(), and current->cred does not go away.

Let's use current_cred() in nfsd_nl_listener_set_doit().

Weakness: CWE-401

Which versions are affected by CVE-2026-43394?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-43394?

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-2026-43394 being exploited?

There is no known exploitation of CVE-2026-43394 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-43394, DEBIAN-CVE-2026-43394, GHSA-h5f4-6rm7-58wm, UBUNTU-CVE-2026-43394.

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