CVE-2026-80842

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A use-after-free issue exists in the bridge multicast component of the Linux kernel. The problem occurs during the teardown of a master VLAN's multicast context. Specifically, the br multicast toggle one vlan() function fails to clear the BR VLFLAG MCAST ENABLED flag and acquire the br->multicast lock for master VLANs because it returns early when br vlan is brentry() is false. Consequently, while br vlan put master() drains and frees the VLAN context via call rcu(), the bridge transmit path in br multicast rcv() may still perceive the context as enabled and attempt to re-arm timers, leading to a memory corruption event in br multicast host join().

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.