{"api_version":"1","generated_at":"2026-08-16T06:00:44+00:00","cve":"CVE-2026-74480","urls":{"html":"https://cve.report/CVE-2026-74480","api":"https://cve.report/api/cve/CVE-2026-74480.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74480","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74480"},"summary":{"title":"net: bridge: stop fast-leave after deleting a port group","description":"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->ports with pp = &p->next 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->ports 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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 13:17:52","updated_at":"2026-08-15 13:17:52"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/159ad90cb929c033308bb39a2c5f8fbf393b77aa","name":"https://git.kernel.org/stable/c/159ad90cb929c033308bb39a2c5f8fbf393b77aa","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a39789f211b8a4125f0c70e05b30cf715f4f187d","name":"https://git.kernel.org/stable/c/a39789f211b8a4125f0c70e05b30cf715f4f187d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4695430e8132420bf8de94da3eb36a6cf35fde6b","name":"https://git.kernel.org/stable/c/4695430e8132420bf8de94da3eb36a6cf35fde6b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0309ebbc570000ea0df11c06b69798e5860c5f6f","name":"https://git.kernel.org/stable/c/0309ebbc570000ea0df11c06b69798e5860c5f6f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4","name":"https://git.kernel.org/stable/c/4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74480","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74480","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6db6f0eae6052b70885562e1733896647ec1d807 159ad90cb929c033308bb39a2c5f8fbf393b77aa git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6db6f0eae6052b70885562e1733896647ec1d807 4695430e8132420bf8de94da3eb36a6cf35fde6b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6db6f0eae6052b70885562e1733896647ec1d807 0309ebbc570000ea0df11c06b69798e5860c5f6f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6db6f0eae6052b70885562e1733896647ec1d807 4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6db6f0eae6052b70885562e1733896647ec1d807 a39789f211b8a4125f0c70e05b30cf715f4f187d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.151 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.103 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.44 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.8 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc6 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/bridge/br_multicast.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"159ad90cb929c033308bb39a2c5f8fbf393b77aa","status":"affected","version":"6db6f0eae6052b70885562e1733896647ec1d807","versionType":"git"},{"lessThan":"4695430e8132420bf8de94da3eb36a6cf35fde6b","status":"affected","version":"6db6f0eae6052b70885562e1733896647ec1d807","versionType":"git"},{"lessThan":"0309ebbc570000ea0df11c06b69798e5860c5f6f","status":"affected","version":"6db6f0eae6052b70885562e1733896647ec1d807","versionType":"git"},{"lessThan":"4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4","status":"affected","version":"6db6f0eae6052b70885562e1733896647ec1d807","versionType":"git"},{"lessThan":"a39789f211b8a4125f0c70e05b30cf715f4f187d","status":"affected","version":"6db6f0eae6052b70885562e1733896647ec1d807","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/bridge/br_multicast.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.11"},{"lessThan":"4.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.151","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.103","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.44","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.8","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc6","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.151","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.103","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.44","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.8","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc6","versionStartIncluding":"4.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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->ports with pp = &p->next 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->ports 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."}],"providerMetadata":{"dateUpdated":"2026-08-15T12:27:13.803Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/159ad90cb929c033308bb39a2c5f8fbf393b77aa"},{"url":"https://git.kernel.org/stable/c/4695430e8132420bf8de94da3eb36a6cf35fde6b"},{"url":"https://git.kernel.org/stable/c/0309ebbc570000ea0df11c06b69798e5860c5f6f"},{"url":"https://git.kernel.org/stable/c/4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4"},{"url":"https://git.kernel.org/stable/c/a39789f211b8a4125f0c70e05b30cf715f4f187d"}],"title":"net: bridge: stop fast-leave after deleting a port group","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74480","datePublished":"2026-08-15T12:27:13.803Z","dateReserved":"2026-08-15T05:44:03.904Z","dateUpdated":"2026-08-15T12:27:13.803Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 13:17:52","lastModifiedDate":"2026-08-15 13:17:52","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74480","Ordinal":"1","Title":"net: bridge: stop fast-leave after deleting a port group","CVE":"CVE-2026-74480","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74480","Ordinal":"1","NoteData":"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->ports with pp = &p->next 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->ports 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.","Type":"Description","Title":"net: bridge: stop fast-leave after deleting a port group"}]}}}