CVE-2026-53220

Local kernel panic via stale bridge-port dereference

Published Jun 25, 2026 · Updated Jun 25, 2026

NULL pointer dereference in Linux Kernel netfilter allows local users to trigger a kernel panic through NFQUEUE reinjection. ebt_redirect_tg() dereferences br_port_get_rcu() without revalidating that the device still belongs to the bridge after userspace removes or reparents its port. Exploitation requires local low-privilege access to alter bridge membership between the original bridge hook and packet reinjection, and the consequence is a host crash.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Linux Kernel netfilter allows local users to trigger a kernel panic through NFQUEUE reinjection. ebt_redirect_tg() dereferences br_port_get_rcu() without revalidating that the device still belongs to the bridge after userspace removes or reparents its port. Exploitation requires local low-privilege access to alter bridge membership between the original bridge hook and packet reinjection, and the consequence is a host crash.

The record

CVE
CVE-2026-53220
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 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=2.6.36
  2. Affected versionversion=f350a0a87374418635689471606454abc7beaa3a <43330a1e8aace6b5a8de9aba127e9e394ab49b0f
  3. Affected versionversion=f350a0a87374418635689471606454abc7beaa3a <4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
  4. Affected versionversion=f350a0a87374418635689471606454abc7beaa3a <ccb9fd4b87538ccf19ccff78ee26700526d94867
  5. Affected versionversion=f350a0a87374418635689471606454abc7beaa3a <d4b1301fd3c9e5e105fd3767c68bc4ba558bb228

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.36; version=f350a0a87374418635689471606454abc7beaa3a <43330a1e8aace6b5a8de9aba127e9e394ab49b0f; version=f350a0a87374418635689471606454abc7beaa3a <4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0; version=f350a0a87374418635689471606454abc7beaa3a <ccb9fd4b87538ccf19ccff78ee26700526d94867; version=f350a0a87374418635689471606454abc7beaa3a <d4b1301fd3c9e5e105fd3767c68bc4ba558bb228

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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-476NULL Pointer Dereference
T1499.004Application 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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