CVE Intelligence
High Memory corruption

CVE-2026-64423 — ipv4: igmp: remove multicast group from hash table on device destruction

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

Published Jul 25, 2026 · Updated Oct 15, 2026 · Sources: CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.1% (30-day exploitation probability)+0
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.13%
ahead of 2% of scored CVEs · Oct 14, 2026
Affects
Linux
Linux and 1 more
CVSS base
7.8
High · 3 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < 412ba7def06ffe974ba9a1d862b022362c54ffa5version 3.11≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < 7993211bde166471dffac074dc965489f86531f8≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < f91883031e5a62877a29ce139442973cbea769f1≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < 2ca18df1c2611f70eb3eb487e02ae85eb703b284≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < 8820b530cb2388503d7418228d03ba074bf7a03e≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < 76d030ac95e17f91d69a595f17ebc5979700cf9a≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < 5f42729d74bd6c61306d864423290d92962de4e1
and 1 more ≥ e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 and < c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9
Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel ≥ 3.11 and < 5.10.261version 7.2-rc2version 7.2-rc1≥ 6.19 and < 7.1.4≥ 6.13 and < 6.18.39≥ 6.7 and < 6.12.96≥ 6.2 and < 6.6.145≥ 5.16 and < 6.1.178
and 1 more ≥ 5.11 and < 5.15.212
Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.8 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-416 · Use After Free

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 15, 2026 · NIST National Vulnerability Database
  • Affected products added · linux/linux kernel
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · Published → Modified
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 15, 2026
  • CVSS changed · 7.8
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Published
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record created in this database
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • CVE published
    Jul 25, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 15, 2026 – Oct 15, 2026
  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

12 on the record

Elsewhere on this site

Linux
every CVE for this vendor
Memory corruption
same class
CWE-416
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 13h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
  • CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No CISA SSVC assessment.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-64423 is "ipv4: igmp: remove multicast group from hash table on device destruction", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.13% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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