A high-severity use-after-free vulnerability in the Linux kernel IPv6 multicast routing subsystem may allow a local authenticated attacker to compromise system integrity and availability.

This is a use-after-free flaw occurring when ip6mr_cache_report attempts to clone a freed destination entry during multicast routing lookups. The vulnerability requires a local attacker with low privileges to manipulate multicast packets, which then triggers the invalid memory access during route resolution.

The vulnerability carries a CVSS score of 7.8, indicating a high risk to system security. Successful exploitation could lead to arbitrary code execution within the kernel context or a complete system crash, resulting in significant service downtime and potential unauthorized access to sensitive kernel-level data.

Immediate Action: Update your Linux kernel to version 7.2.6 or later, or apply the specific upstream patches identified in the Linux stable git repositories.

Proactive Monitoring: Monitor system logs for kernel panic events or memory-related errors that may indicate exploitation attempts against the IPv6 stack.

Compensating Controls: Restrict access to multicast routing functions and limit the ability of non-privileged users to interact with raw sockets if such operations are not required for system functionality.

Public Exploit Available: Unknown.

Given the severity of a kernel-level use-after-free, organizations should prioritize patching their Linux environments. Ensure that kernel updates are tested in staging environments before deployment to production, and verify that the specific commits or version 7.2.6 are included in your distribution's latest security kernel releases.