CVE Catalog

CVE-2026-52928

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

6th percentile - higher than 6% of all known CVEs

Summary

A vulnerability was found in the Linux kernel's AF_UNIX socket implementation. The SIOCATMARK ioctl, which reports the urgent data mark position (MSG_OOB), was accessible for all socket types, even though MSG_OOB is only supported for SOCK_STREAM. For SOCK_DGRAM and SOCK_SEQPACKET sockets, which reject MSG_OOB, the call now returns -EOPNOTSUPP.

Risk Assessment

Organizations may face incorrect behavior in applications using AF_UNIX sockets of type SOCK_DGRAM or SOCK_SEQPACKET, which could misinterpret the receive queue state as containing urgent data, leading to logic errors or potential security breaches.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit 0b7f0b1e5c1e in the mainline branch or appropriate backports for your distribution). A system reboot is required after the update.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS