CVE intelligence

CVE-2026-74480

Vulnerability intelligence

Published Aug 15, 2026Sources checked Oct 28, 2026

9.8CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-74480 and is rated Critical severity with a CVSS score of 9.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 2, 2026

Release Notes

Vendor-listed releases

6.6.152.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.6%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-74480?

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

net: bridge: stop fast-leave after deleting a port group

br_multicast_leave_group() iterates mp->ports with pp = &p->next in its fast-leave path. After br_multicast_del_pg() removes p, continuing the loop advances pp through the deleted entry.

If multicast-to-unicast was enabled, the bridge can hold multiple port groups for the same port and group with different source MAC addresses. Once multicast-to-unicast is disabled, br_port_group_equal() matches those entries by port only.

A fast leave can then delete one entry and continue from its stale next pointer, leaving mp->ports pointing at a deleted port group.

Fast leave only needs to remove one matching port group. Break after br_multicast_del_pg() so the loop stops before dereferencing the removed entry.

Source: NVD