Answer in brief
CVE-2026-64423 records a Unknown severity vulnerability in ipv4: igmp: remove multicast group from hash table on device destruction. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-64423 records a Unknown severity vulnerability in ipv4: igmp: remove multicast group from hash table on device destruction. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <412ba7def06ffe974ba9a1d862b022362c54ffa5 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <5f42729d74bd6c61306d864423290d92962de4e1 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <76d030ac95e17f91d69a595f17ebc5979700cf9a || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <8820b530cb2388503d7418228d03ba074bf7a03e || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <2ca18df1c2611f70eb3eb487e02ae85eb703b284 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <f91883031e5a62877a29ce139442973cbea769f1 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <7993211bde166471dffac074dc965489f86531f8 | 412ba7def06ffe974ba9a1d862b022362c54ffa5, c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9, 5f42729d74bd6c61306d864423290d92962de4e1, 76d030ac95e17f91d69a595f17ebc5979700cf9a, 8820b530cb2388503d7418228d03ba074bf7a03e, 2ca18df1c2611f70eb3eb487e02ae85eb703b284, f91883031e5a62877a29ce139442973cbea769f1, 7993211bde166471dffac074dc965489f86531f8 |
| Linux/Linuxgeneric | 3.11 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: remove multicast group from hash table on device destruction When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through the multicast list and calls ip_ma_put() on each membership, scheduling them for RCU reclamation. However, they are not unlinked from the device's multicast hash table (mc_hash). Since the device remains published in dev->ip_ptr until after ip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash can still locate and access the multicast group after its refcount is decremented. If the RCU callback runs and frees the group while a reader is accessing it, a use-after-free occurs. Fix this by unlinking the multicast group from mc_hash using ip_mc_hash_remove() before scheduling it for reclamation. BUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0 Read of size 4 at addr ffff888009bf1408 by task mausezahn/2276 Call Trace: <IRQ> dump_stack_lvl+0x67/0x90 print_report+0x175/0x7c0 kasan_report+0x147/0x180 ip_check_mc_rcu+0x149/0x3f0 udp_v4_early_demux+0x36d/0x12d0 ip_rcv_finish_core+0xb8b/0x1390 ip_rcv_finish+0x54/0x120 NF_HOOK+0x213/0x2b0 __netif_receive_skb+0x126/0x340 process_backlog+0x4f2/0xf00 __napi_poll+0x92/0x2c0 net_rx_action+0x583/0xc60 handle_softirqs+0x236/0x7f0 do_softirq+0x57/0x80 </IRQ> Allocated by task 2239: kasan_save_track+0x3e/0x80 __kasan_kmalloc+0x72/0x90 ____ip_mc_inc_group+0x31a/0xa40 __ip_mc_join_group+0x334/0x3f0 do_ip_setsockopt+0x16fa/0x2010 ip_setsockopt+0x3f/0x90 do_sock_setsockopt+0x1ad/0x300 Freed by task 0: kasan_save_track+0x3e/0x80 kasan_save_free_info+0x40/0x50 __kasan_slab_free+0x3a/0x60 __rcu_free_sheaf_prepare+0xd4/0x220 rcu_free_sheaf+0x36/0x190 rcu_core+0x8d9/0x12f0 handle_softirqs+0x236/0x7f0
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <412ba7def06ffe974ba9a1d862b022362c54ffa5 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <5f42729d74bd6c61306d864423290d92962de4e1 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <76d030ac95e17f91d69a595f17ebc5979700cf9a || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <8820b530cb2388503d7418228d03ba074bf7a03e || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <2ca18df1c2611f70eb3eb487e02ae85eb703b284 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <f91883031e5a62877a29ce139442973cbea769f1 || >=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <7993211bde166471dffac074dc965489f86531f8 | 412ba7def06ffe974ba9a1d862b022362c54ffa5, c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9, 5f42729d74bd6c61306d864423290d92962de4e1, 76d030ac95e17f91d69a595f17ebc5979700cf9a, 8820b530cb2388503d7418228d03ba074bf7a03e, 2ca18df1c2611f70eb3eb487e02ae85eb703b284, f91883031e5a62877a29ce139442973cbea769f1, 7993211bde166471dffac074dc965489f86531f8 |
| Linux/Linuxgeneric | 3.11 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: remove multicast group from hash table on device destruction When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through the multicast list and calls ip_ma_put() on each membership, scheduling them for RCU reclamation. However, they are not unlinked from the device's multicast hash table (mc_hash). Since the device remains published in dev->ip_ptr until after ip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash can still locate and access the multicast group after its refcount is decremented. If the RCU callback runs and frees the group while a reader is accessing it, a use-after-free occurs. Fix this by unlinking the multicast group from mc_hash using ip_mc_hash_remove() before scheduling it for reclamation. BUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0 Read of size 4 at addr ffff888009bf1408 by task mausezahn/2276 Call Trace: <IRQ> dump_stack_lvl+0x67/0x90 print_report+0x175/0x7c0 kasan_report+0x147/0x180 ip_check_mc_rcu+0x149/0x3f0 udp_v4_early_demux+0x36d/0x12d0 ip_rcv_finish_core+0xb8b/0x1390 ip_rcv_finish+0x54/0x120 NF_HOOK+0x213/0x2b0 __netif_receive_skb+0x126/0x340 process_backlog+0x4f2/0xf00 __napi_poll+0x92/0x2c0 net_rx_action+0x583/0xc60 handle_softirqs+0x236/0x7f0 do_softirq+0x57/0x80 </IRQ> Allocated by task 2239: kasan_save_track+0x3e/0x80 __kasan_kmalloc+0x72/0x90 ____ip_mc_inc_group+0x31a/0xa40 __ip_mc_join_group+0x334/0x3f0 do_ip_setsockopt+0x16fa/0x2010 ip_setsockopt+0x3f/0x90 do_sock_setsockopt+0x1ad/0x300 Freed by task 0: kasan_save_track+0x3e/0x80 kasan_save_free_info+0x40/0x50 __kasan_slab_free+0x3a/0x60 __rcu_free_sheaf_prepare+0xd4/0x220 rcu_free_sheaf+0x36/0x190 rcu_core+0x8d9/0x12f0 handle_softirqs+0x236/0x7f0
Quoted source text, attributed separately from HOL analysis.