Use After Free Affecting kernel-livepatch-6.12.113-138.209 package, versions <1:1.0-0.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.16% (6th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELLIVEPATCH612113138209-21807751
  • published29 Oct 2026
  • disclosed18 Oct 2026

Introduced: 18 Oct 2026

NewCVE-2026-98487  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-livepatch-6.12.113-138.209 to version 1:1.0-0.amzn2023 or higher.
This issue was patched in ALAS2023-2026-3335.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-livepatch-6.12.113-138.209 package and not the kernel-livepatch-6.12.113-138.209 package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1