CVE-2026-98487

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-09-25 10:25 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-10-18 16:16 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-24 14:16 UTC Last updatedMost recent change to the record

Details

Published

2026-10-18 16:16 UTC

Last modified

2026-10-24 14:16 UTC

Exploit probability

0.2% · EPSS, next 30 days

Record status

Received

Attack profile CVSS 3.1 · 7.8

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High