CVE-2026-98026
Received
Received - Intake
Use-After-Free in Linux Kernel Bridge Multicast
Vulnerability report for CVE-2026-98026, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-25
Last updated on: 2026-09-25
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: mcast: properly convert mglist to rcu
Sashiko reported a bug [1] that br_multicast_del_port_group unlists the
port group not using proper rcu helper that preserves the next pointer and
after that immediately frees the port group without waiting for rcu grace
period. The only rcu walker of mglist is br_multicast_list_adjacent() and
it turns out that function has always been buggy because mglist was never
properly converted to RCU. Fix it by converting it to rcu and moving its
initialization after eth_addr's. Initializing p->next can use
RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call
later, besides we're initializing an unpublished structure anyway.
[1] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260826014200.362304-1-littleddfu%40gmail.com
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
