{"id":"CVE-2026-98487","summary":"net: bridge: mdb: restart port group walk after deletion","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: mdb: restart port group walk after deletion\n\nbr_mdb_flush_pgs() keeps a pointer-to-pointer cursor while walking\nmp-\u003eports. br_multicast_del_pg() can re-enter the same MDB entry through\nbr_multicast_sg_del_exclude_ports() and unlink other port groups. If the\ncursor points into one of those groups, the next iteration dereferences a\nstale cursor and can leave mp-\u003eports pointing at freed memory.\n\nA following RTM_GETMDB exposes the dangling pointer:\n\n  BUG: KASAN: slab-use-after-free in br_mdb_dump\n  Read of size 8\n    br_mdb_dump\n    rtnl_mdb_dump\n    rtnl_dumpit\n    netlink_dump\n\nReset the cursor to mp-\u003eports after every deletion. The deletion removes at\nleast the selected group, so the restarted walk always makes progress.","modified":"2026-10-19T02:45:50.687498911Z","published":"2026-10-18T15:16:04.746Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98487.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/46ec55855c972504258c371677ac039ba20e5d12"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ab1404ac81154a89fb61ac50ae9a04cd8d4834dc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fe2a42789c12eb7c5d3a42191e2cc735a6c35ead"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98487.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98487"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a6acb535afb2a3b688a7858f05b61f0433e480d5"},{"fixed":"46ec55855c972504258c371677ac039ba20e5d12"},{"fixed":"ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe"},{"fixed":"fe2a42789c12eb7c5d3a42191e2cc735a6c35ead"},{"fixed":"ab1404ac81154a89fb61ac50ae9a04cd8d4834dc"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98487.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.8.0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.55"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98487.json"}}],"schema_version":"1.9.0"}