CVE-2026-98487

net: bridge: mdb: restart port group walk after deletion

HIGH
7.8
CVSS Score
Published: October 18, 2026 at 03:16 PM UTC
Updated: October 24, 2026 at 02:16 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mdb: restart port group walk after deletion br_mdb_flush_pgs() keeps a pointer-to-pointer cursor while walking mp->ports. br_multicast_del_pg() can re-enter the same MDB entry through br_multicast_sg_del_exclude_ports() and unlink other port groups. If the cursor points into one of those groups, the next iteration dereferences a stale cursor and can leave mp->ports pointing at freed memory. A following RTM_GETMDB exposes the dangling pointer: BUG: KASAN: slab-use-after-free in br_mdb_dump Read of size 8 br_mdb_dump rtnl_mdb_dump rtnl_dumpit netlink_dump Reset the cursor to mp->ports after every deletion. The deletion removes at least the selected group, so the restarted walk always makes progress.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.8a6acb535afb2a3b688a7858f05b61f0433e480d5
Vendor states this is fixed in 6.12.112 (unaffected)
Vendor states this is fixed in 6.18.55 (unaffected)
Vendor states this is fixed in 7.2.9 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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