{"id":"CVE-2026-74480","summary":"net: bridge: stop fast-leave after deleting a port group","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: stop fast-leave after deleting a port group\n\nbr_multicast_leave_group() iterates mp-\u003eports with pp = &p-\u003enext in\nits fast-leave path. After br_multicast_del_pg() removes p,\ncontinuing the loop advances pp through the deleted entry.\n\nIf multicast-to-unicast was enabled, the bridge can hold multiple port\ngroups for the same port and group with different source MAC\naddresses. Once multicast-to-unicast is disabled,\nbr_port_group_equal() matches those entries by port only. A fast leave\ncan then delete one entry and continue from its stale next pointer,\nleaving mp-\u003eports pointing at a deleted port group.\n\nFast leave only needs to remove one matching port group. Break after\nbr_multicast_del_pg() so the loop stops before dereferencing the\nremoved entry.","modified":"2026-08-21T03:30:24.764144797Z","published":"2026-08-15T12:27:13.803Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74480.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0309ebbc570000ea0df11c06b69798e5860c5f6f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/159ad90cb929c033308bb39a2c5f8fbf393b77aa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1a109cc9890d017c41d77e6c82da739579c49f0b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4695430e8132420bf8de94da3eb36a6cf35fde6b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/482bcb85139addb4e8ac8ed10baeda3e0aad4031"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a39789f211b8a4125f0c70e05b30cf715f4f187d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d6c32e2e25a9a06ba021030e26b6d602a277eb72"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74480.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74480"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6db6f0eae6052b70885562e1733896647ec1d807"},{"fixed":"d6c32e2e25a9a06ba021030e26b6d602a277eb72"},{"fixed":"482bcb85139addb4e8ac8ed10baeda3e0aad4031"},{"fixed":"1a109cc9890d017c41d77e6c82da739579c49f0b"},{"fixed":"159ad90cb929c033308bb39a2c5f8fbf393b77aa"},{"fixed":"4695430e8132420bf8de94da3eb36a6cf35fde6b"},{"fixed":"0309ebbc570000ea0df11c06b69798e5860c5f6f"},{"fixed":"4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4"},{"fixed":"a39789f211b8a4125f0c70e05b30cf715f4f187d"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74480.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.11.0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.151"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.103"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.44"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74480.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}