CVE-2026-72254

System crash via invalid netdev fib expression

Published Aug 15, 2026 · Updated Aug 15, 2026

NULL pointer dereference in Linux kernel 5.16 and later allows local users to crash the system through a netdev egress fib expression. nft_fib_validate() applies NF_INET hook masks to the separate netdev hook enum, so the aliased egress value passes validation and nft_in(pkt) is dereferenced as NULL during evaluation. Reachability requires permission to create the affected nftables netdev egress chain; successful triggering interrupts the entire host by crashing its kernel.

CVSS severity5.5
Medium
EPSS probability0.60%
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 5.16 and later allows local users to crash the system through a netdev egress fib expression. nft_fib_validate() applies NF_INET hook masks to the separate netdev hook enum, so the aliased egress value passes validation and nft_in(pkt) is dereferenced as NULL during evaluation. Reachability requires permission to create the affected nftables netdev egress chain; successful triggering interrupts the entire host by crashing its kernel.

The record

CVE
CVE-2026-72254
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

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=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <4fee43759b489559a491f7c95f9bfa7a1d0c7a10
  2. Affected versionversion=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <568931f26af4727a51e8521f72efbc78d3b82410
  3. Affected versionversion=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <d01c913febead04a01a5f3a6374d1f45504dc523
  4. Affected versionversion=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <d07955dd34ecae17d35d8c7d0a273a3fba653a8c
  5. Affected versionversion=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <f68305267ebda7e839b5e8f77e8d77535a3d5a0f
  6. Affected versionversion=5.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <4fee43759b489559a491f7c95f9bfa7a1d0c7a10; version=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <568931f26af4727a51e8521f72efbc78d3b82410; version=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <d01c913febead04a01a5f3a6374d1f45504dc523; version=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <d07955dd34ecae17d35d8c7d0a273a3fba653a8c; version=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <f68305267ebda7e839b5e8f77e8d77535a3d5a0f; version=5.16

Published CVSS scores

5.5OracleCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.4Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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
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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