CVE-2026-64032

Local system crash via stale multicast timer

Published Jul 19, 2026 · Updated Jul 19, 2026

Use-after-free in Linux Kernel bridge multicast code allows local users to crash the system when removing a configured bridge port. When per-VLAN multicast snooping is enabled, br_multicast_disable_port() can leave the per-port multicast context and its timer enabled after the bridge port is freed. Reachability requires local low-privileged access and a port that acquired both per-port and per-VLAN multicast contexts through snooping-mode changes.

CVSS severity7.8
High
EPSS probability0.13%
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 Linux Kernel bridge multicast code allows local users to crash the system when removing a configured bridge port. When per-VLAN multicast snooping is enabled, br_multicast_disable_port() can leave the per-port multicast context and its timer enabled after the bridge port is freed. Reachability requires local low-privileged access and a port that acquired both per-port and per-VLAN multicast contexts through snooping-mode changes.

The record

CVE
CVE-2026-64032
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-825, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=410a033bfa8c7daefbae0225c836693db2149ec1 <ddefd1b8e5eb58933a697ab38334f0fd82e7fb8b
  2. Affected versionversion=4b30ae9adb047dd0a7982975ec3933c529537026 <4df78ff02629c7729168f0696a7a2123c389818d
  3. Affected versionversion=4b30ae9adb047dd0a7982975ec3933c529537026 <7213256c91ed778a0997c2029c152b18dc50e4fd
  4. Affected versionversion=4b30ae9adb047dd0a7982975ec3933c529537026 <a9224862d597d0eed0a34bbb27343f703fc4113f
  5. Affected versionversion=5.15.186 <5.15.209
  6. Affected versionversion=6.1.142 <6.1.175
  7. Affected versionversion=6.12.35 <6.12.92
  8. Affected versionversion=6.15.4 <6.16
  9. Affected versionversion=6.16
  10. Affected versionversion=6.6.95 <6.6.142
  11. Affected versionversion=78f768e36c065ca3f88272fcf39014782c2d4ecd <ebe5561154c823b323bd06e350b55e0b8604d851
  12. Affected versionversion=b4c83b37490d61cfdd62a2b29e98a9b89004b5c0 <1900ca8acb92fbea8bf9abef9927c7fed03db7fc
  13. Affected versionversion=c6d16eab122744df698f18b47cf771945cd55066 <ed3b69e60385a03df11c6d12e5d7bdf0f4a11b70
  14. Affected versionversion=c996e25df0b3282c724bb5aca434518bc08cd963

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=410a033bfa8c7daefbae0225c836693db2149ec1 <ddefd1b8e5eb58933a697ab38334f0fd82e7fb8b; version=4b30ae9adb047dd0a7982975ec3933c529537026 <4df78ff02629c7729168f0696a7a2123c389818d; version=4b30ae9adb047dd0a7982975ec3933c529537026 <7213256c91ed778a0997c2029c152b18dc50e4fd; version=4b30ae9adb047dd0a7982975ec3933c529537026 <a9224862d597d0eed0a34bbb27343f703fc4113f; version=5.15.186 <5.15.209; version=6.1.142 <6.1.175; version=6.12.35 <6.12.92; version=6.15.4 <6.16; version=6.16; version=6.6.95 <6.6.142; version=78f768e36c065ca3f88272fcf39014782c2d4ecd <ebe5561154c823b323bd06e350b55e0b8604d851; version=b4c83b37490d61cfdd62a2b29e98a9b89004b5c0 <1900ca8acb92fbea8bf9abef9927c7fed03db7fc; version=c6d16eab122744df698f18b47cf771945cd55066 <ed3b69e60385a03df11c6d12e5d7bdf0f4a11b70; version=c996e25df0b3282c724bb5aca434518bc08cd963

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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