Riskcovery

CVE-2026-98487

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

State
Published
Severity
7.8 High
Published
Oct 18, 2026
Updated
Oct 24, 2026
Reserved
Sep 25, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • a6acb535afb2a3b688a7858f05b61f0433e480d5 to before 46ec55855c972504258c371677ac039ba20e5d12Affected
  • a6acb535afb2a3b688a7858f05b61f0433e480d5 to before ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7feAffected
  • a6acb535afb2a3b688a7858f05b61f0433e480d5 to before fe2a42789c12eb7c5d3a42191e2cc735a6c35eadAffected
  • a6acb535afb2a3b688a7858f05b61f0433e480d5 to before ab1404ac81154a89fb61ac50ae9a04cd8d4834dcAffected
LinuxLinux
  • 6.8Affected
  • before 6.8Not affected
  • 6.12.112 through 6.12.*Not affected
  • 6.18.55 through 6.18.*Not affected
  • 7.2.9 through 7.2.*Not affected
  • 7.3 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.