CVE-2026-98487net: bridge: mdb: restart port group walk after deletion
- 7.8HighCVSS base score
- 0.16%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 23 days later
· 23 days later
Published
- 6 days later
· 6 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.16% · top 94% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected a6acb535afb2a3b688a7858f05b61f0433e480d5 – < 46ec55855c972504258c371677ac039ba20e5d12
- affected a6acb535afb2a3b688a7858f05b61f0433e480d5 – < ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe
- affected a6acb535afb2a3b688a7858f05b61f0433e480d5 – < fe2a42789c12eb7c5d3a42191e2cc735a6c35ead
- affected a6acb535afb2a3b688a7858f05b61f0433e480d5 – < ab1404ac81154a89fb61ac50ae9a04cd8d4834dc
- affected 6.8
- unaffected < 6.8
- unaffected 6.12.112 – ≤ 6.12.*
- unaffected 6.18.55 – ≤ 6.18.*
- unaffected 7.2.9 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References4
- https://git.kernel.org/stable/c/46ec55855c972504258c371677ac039ba20e5d12 (opens in a new tab)
- https://git.kernel.org/stable/c/ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe (opens in a new tab)
- https://git.kernel.org/stable/c/fe2a42789c12eb7c5d3a42191e2cc735a6c35ead (opens in a new tab)
- https://git.kernel.org/stable/c/ab1404ac81154a89fb61ac50ae9a04cd8d4834dc (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-103727 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-98487)Record last updated .