CVE-2026-53181 Affecting kernel-rt-kvm package, versions *


Severity

Recommended
medium

Based on CentOS security rating.

Threat Intelligence

EPSS
0.18% (9th percentile)

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  • Snyk IDSNYK-CENTOS10-KERNELRTKVM-17698533
  • published30 Jun 2026
  • disclosed25 Jun 2026

Introduced: 25 Jun 2026

NewCVE-2026-53181  (opens in a new tab)

How to fix?

There is no fixed version for Centos:10 kernel-rt-kvm.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-kvm package and not the kernel-rt-kvm package as distributed by Centos. See How to fix? for Centos:10 relevant fixed versions and status.

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

vsock/vmci: fix sk_ack_backlog leak on failed handshake

When vmci_transport_recv_connecting_server() returns an error, vmci_transport_recv_listen() calls vsock_remove_pending() but never calls sk_acceptq_removed(). This leaves sk_ack_backlog incremented permanently.

Repeated handshake failures (malformed packets, queue pair alloc failure, event subscribe failure) cause sk_ack_backlog to climb toward sk_max_ack_backlog. Once it reaches the limit the listener permanently refuses all new connections with -ECONNREFUSED, a silent denial of service requiring a process restart to recover.

The two existing sk_acceptq_removed() calls in af_vsock.c do not cover this path: line 764 checks vsock_is_pending() which returns false after vsock_remove_pending(), and line 1889 is only reached on successful accept().

Fix by balancing sk_acceptq_added() with sk_acceptq_removed() on the error path.

CVSS Base Scores

version 3.1