CVE-2026-52928 af_unix: Reject SIOCATMARK on non-stream sockets

What is CVE-2026-52928?

CVE-2026-52928 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:

af_unix: Reject SIOCATMARK on non-stream sockets

SIOCATMARK reports whether the receive queue is at the urgent mark for MSG_OOB.

In AF_UNIX, MSG_OOB is supported only for SOCK_STREAM sockets. SOCK_DGRAM and SOCK_SEQPACKET reject MSG_OOB in sendmsg() and recvmsg(), so they should not support SIOCATMARK either.

Return -EOPNOTSUPP for non-stream sockets before checking the receive queue.

Which versions are affected by CVE-2026-52928?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-52928?

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-2026-52928 being exploited?

There is no known exploitation of CVE-2026-52928 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 AZL-90425, BELL-CVE-2026-52928, DEBIAN-CVE-2026-52928, GHSA-3jxv-h97q-rq3x, ROOT-OS-DEBIAN-12-CVE-2026-52928, ROOT-OS-UBUNTU-2204-CVE-2026-52928 and 2 more.