net: bridge: mdb: restart port group walk after deletion
Summary
| CVE | CVE-2026-98487 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-18 16:16:59 UTC |
| Updated | 2026-10-24 14:16:43 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected a6acb535afb2a3b688a7858f05b61f0433e480d5 46ec55855c972504258c371677ac039ba20e5d12 git | Not specified |
| CNA | Linux | Linux | affected a6acb535afb2a3b688a7858f05b61f0433e480d5 ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe git | Not specified |
| CNA | Linux | Linux | affected a6acb535afb2a3b688a7858f05b61f0433e480d5 fe2a42789c12eb7c5d3a42191e2cc735a6c35ead git | Not specified |
| CNA | Linux | Linux | affected a6acb535afb2a3b688a7858f05b61f0433e480d5 ab1404ac81154a89fb61ac50ae9a04cd8d4834dc git | Not specified |
| CNA | Linux | Linux | affected 6.8 | Not specified |
| CNA | Linux | Linux | unaffected 6.8 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.112 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.55 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.9 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ab1404ac81154a89fb61ac50ae9a04cd8d4834dc | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/fe2a42789c12eb7c5d3a42191e2cc735a6c35ead | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/46ec55855c972504258c371677ac039ba20e5d12 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.