CVE-2026-53080Public exploit

Kernel crash via premature cls_fw filter publication

Published Jun 24, 2026 · Updated Jun 24, 2026

NULL pointer dereference in the Linux Kernel cls_fw classifier allows local users to crash the kernel through traffic-control filters. The datapath can call fw_classify() after an invalid old-style filter is published to a shared block but before change() initializes it, causing q->handle to dereference a NULL q pointer. Triggering the race requires local low privileges and repeated filter creation while marked packets traverse the shared block; the resulting kernel oops interrupts the host.

CVSS severity5.5
Medium
EPSS probability0.11%
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 the Linux Kernel cls_fw classifier allows local users to crash the kernel through traffic-control filters. The datapath can call fw_classify() after an invalid old-style filter is published to a shared block but before change() initializes it, causing q->handle to dereference a NULL q pointer. Triggering the race requires local low privileges and repeated filter creation while marked packets traverse the shared block; the resulting kernel oops interrupts the host.

The record

CVE
CVE-2026-53080
Published
Jun 24, 2026
Updated
Jun 24, 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 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 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=5.1
  2. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <41845bc5bb64f3d615abe575ad655b5e7f193634
  3. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <4fabcfea7a9dd159df32c5df6587fe858cb0d748
  4. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <5dcce34c57d5e5990869384d69deeb9414bf9b92
  5. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <5df49f0579f7e625f2358a219d31fbc7621be799
  6. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <65782b2db7321d5f97c16718c4c7f6c7205a56be
  7. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <829808cbf8cf8a6d07a0e67a5ea2c3fcd63a9e5c
  8. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <a719275da488835e987d28effc04679b4aace3a0
  9. Affected versionversion=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <c205da704c84eeb4247d770150440294fd547049

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.1; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <41845bc5bb64f3d615abe575ad655b5e7f193634; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <4fabcfea7a9dd159df32c5df6587fe858cb0d748; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <5dcce34c57d5e5990869384d69deeb9414bf9b92; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <5df49f0579f7e625f2358a219d31fbc7621be799; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <65782b2db7321d5f97c16718c4c7f6c7205a56be; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <829808cbf8cf8a6d07a0e67a5ea2c3fcd63a9e5c; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <a719275da488835e987d28effc04679b4aace3a0; version=ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 <c205da704c84eeb4247d770150440294fd547049

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 exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

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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