CVE-2026-31503

A flaw was found in the Linux kernel's User Datagram Protocol (UDP) implementation. When a significant number of UDP sockets are bound to specific local addresses on the same port, the kernel's conflict detection mechanism can fail. This allows a local attacker to bind to a wildcard address on a port that should already be in use, potentially leading to a Denial of Service (DoS) for legitimate applications attempting to use that port.

This Moderate impact flaw in the Linux kernel's UDP implementation could allow a local attacker to cause a denial of service. The vulnerability occurs when a large number of UDP sockets are bound to distinct local addresses on the same port, leading to a failure in the kernel's port conflict detection for wildcard binds. This allows an attacker to hijack a port that should be in use by a legitimate application.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.