CVE-2026-72323

Kernel panic via IGMP timer use-after-free

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in the Linux kernel allows remote attackers on an adjacent network to trigger a kernel panic via a crafted IGMP query. The igmp_gq_start_timer() path re-arms a timer and increments an in_device reference after inetdev_destroy() has reduced its refcount to zero, although RCU has only deferred freeing the object. Exploitation requires an IGMP query to race with network-device teardown; timer expiry then dereferences freed memory and crashes the kernel.

CVSS severity9.8
Critical
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel allows remote attackers on an adjacent network to trigger a kernel panic via a crafted IGMP query. The igmp_gq_start_timer() path re-arms a timer and increments an in_device reference after inetdev_destroy() has reduced its refcount to zero, although RCU has only deferred freeing the object. Exploitation requires an IGMP query to race with network-device teardown; timer expiry then dereferences freed memory and crashes the kernel.

The record

CVE
CVE-2026-72323
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-825, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <165258303357e54b75fc19b341ae2a2b7c9e3910
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40a1e998cb266ed4cb529a0bb4fee2b0ba732702
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <75e984fe0cb9e7fbde0c8ee838c61ce8573d3ea3
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7b19c0f81ed1fdaec6bc522569be367199a9edf3
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8d4394ffa40508e0de72f464af351f6ca6a6cdc3
  6. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <165258303357e54b75fc19b341ae2a2b7c9e3910; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40a1e998cb266ed4cb529a0bb4fee2b0ba732702; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <75e984fe0cb9e7fbde0c8ee838c61ce8573d3ea3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7b19c0f81ed1fdaec6bc522569be367199a9edf3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8d4394ffa40508e0de72f464af351f6ca6a6cdc3; version=2.6.12

Published CVSS scores

5.9Amazon LinuxCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
9.8cve.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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