{"id":"CVE-2026-64423","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: igmp: remove multicast group from hash table on device destruction\n\nWhen a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through\nthe multicast list…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: igmp: remove multicast group from hash table on device destruction\n\nWhen a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through\nthe multicast list…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.11, < 5.10.261","linux_kernel >= 5.11, < 5.15.212","linux_kernel >= 5.16, < 6.1.178","linux_kernel >= 6.2, < 6.6.145","linux_kernel >= 6.7, < 6.12.96","linux_kernel >= 6.13, < 6.18.39","linux_kernel >= 6.19, < 7.1.4","linux_kernel = 7.2"],"patched":["linux_kernel 7.1.4"],"published":"2026-07-25","updated":"2026-09-08","sourceUpdated":"2026-09-08T09:18:19.463","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64423","references":[{"url":"https://git.kernel.org/stable/c/2ca18df1c2611f70eb3eb487e02ae85eb703b284","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/412ba7def06ffe974ba9a1d862b022362c54ffa5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5f42729d74bd6c61306d864423290d92962de4e1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/76d030ac95e17f91d69a595f17ebc5979700cf9a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7993211bde166471dffac074dc965489f86531f8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8820b530cb2388503d7418228d03ba074bf7a03e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f91883031e5a62877a29ce139442973cbea769f1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00128,"epssPercentile":0.02789,"ingestedAt":"2026-09-08T15:33:26.949Z","slug":"CVE-2026-64423","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nipv4: igmp: remove multicast group from hash table on device destruction\n\nWhen a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through\nthe multicast list and calls ip_ma_put() on each membership, scheduling\nthem for RCU reclamation. However, they are not unlinked from the device's\nmulticast hash table (mc_hash).\n\nSince the device remains published in dev->ip_ptr until after\nip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash\ncan still locate and access the multicast group after its refcount is\ndecremented. If the RCU callback runs and frees the group while a reader is\naccessing it, a use-after-free occurs.\n\nFix this by unlinking the multicast group from mc_hash using\nip_mc_hash_remove() before scheduling it for reclamation.\n\nBUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0\nRead of size 4 at addr ffff888009bf1408 by task mausezahn/2276\n\nCall Trace:\n <IRQ>\n dump_stack_lvl+0x67/0x90\n print_report+0x175/0x7c0\n kasan_report+0x147/0x180\n ip_check_mc_rcu+0x149/0x3f0\n udp_v4_early_demux+0x36d/0x12d0\n ip_rcv_finish_core+0xb8b/0x1390\n ip_rcv_finish+0x54/0x120\n NF_HOOK+0x213/0x2b0\n __netif_receive_skb+0x126/0x340\n process_backlog+0x4f2/0xf00\n __napi_poll+0x92/0x2c0\n net_rx_action+0x583/0xc60\n handle_softirqs+0x236/0x7f0\n do_softirq+0x57/0x80\n </IRQ>\n\nAllocated by task 2239:\n kasan_save_track+0x3e/0x80\n __kasan_kmalloc+0x72/0x90\n ____ip_mc_inc_group+0x31a/0xa40\n __ip_mc_join_group+0x334/0x3f0\n do_ip_setsockopt+0x16fa/0x2010\n ip_setsockopt+0x3f/0x90\n do_sock_setsockopt+0x1ad/0x300\n\nFreed by task 0:\n kasan_save_track+0x3e/0x80\n kasan_save_free_info+0x40/0x50\n __kasan_slab_free+0x3a/0x60\n __rcu_free_sheaf_prepare+0xd4/0x220\n rcu_free_sheaf+0x36/0x190\n rcu_core+0x8d9/0x12f0\n handle_softirqs+0x236/0x7f0\n\n## Affected\n\n- `linux_kernel >= 3.11, < 5.10.261`\n- `linux_kernel >= 5.11, < 5.15.212`\n- `linux_kernel >= 5.16, < 6.1.178`\n- `linux_kernel >= 6.2, < 6.6.145`\n- `linux_kernel >= 6.7, < 6.12.96`\n- `linux_kernel >= 6.13, < 6.18.39`\n- `linux_kernel >= 6.19, < 7.1.4`\n- `linux_kernel = 7.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.1.4`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}