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VulnerabilityPublished Updated

CVE-2026-64423: Linux kernel · Use After Free

Source GCVE Database

0

Mentioned vulnerabilities

Authoritative record:CVE-2026-64423· High 7.8

Not known to be exploited · CVSS 7.8 High · fixed in f91883031e5a62877a29ce139442973cbea769f1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in f91883031e5a62877a29ce139442973cbea769f1, c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9, 7993211bde166471dffac074dc965489f86531f8 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7, < f91883031e5a62877a29ce139442973cbea769f1
Fixed in
  • f91883031e5a62877a29ce139442973cbea769f1
LinuxLinuxAffected
  • ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7, < c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9
Fixed in
  • c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9
LinuxLinuxAffected
  • ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7, < 7993211bde166471dffac074dc965489f86531f8
Fixed in
  • 7993211bde166471dffac074dc965489f86531f8
LinuxLinuxAffected
  • ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7, < 8820b530cb2388503d7418228d03ba074bf7a03e
Fixed in
  • 8820b530cb2388503d7418228d03ba074bf7a03e
LinuxLinuxAffected
  • ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7, < 412ba7def06ffe974ba9a1d862b022362c54ffa5
Fixed in
  • 412ba7def06ffe974ba9a1d862b022362c54ffa5
LinuxLinuxAffected
  • ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7, < 76d030ac95e17f91d69a595f17ebc5979700cf9a
Fixed in
  • 76d030ac95e17f91d69a595f17ebc5979700cf9a

Description

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

References

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