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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.56% probability · 45th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0309ebbc570000ea0df11c06b69798e5860c5f6f
- https://git.kernel.org/stable/c/159ad90cb929c033308bb39a2c5f8fbf393b77aa
- https://git.kernel.org/stable/c/1a109cc9890d017c41d77e6c82da739579c49f0b
- https://git.kernel.org/stable/c/4695430e8132420bf8de94da3eb36a6cf35fde6b
- https://git.kernel.org/stable/c/482bcb85139addb4e8ac8ed10baeda3e0aad4031
- https://git.kernel.org/stable/c/4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4
- https://git.kernel.org/stable/c/a39789f211b8a4125f0c70e05b30cf715f4f187d
- https://git.kernel.org/stable/c/d6c32e2e25a9a06ba021030e26b6d602a277eb72
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.