CVE-2026-31563Network attack vector

Remote service interruption via IRQ-disabled TX buffer free

Published Apr 24, 2026 · Updated Apr 24, 2026

Denial of service in the Linux Kernel MACB/GEM network driver allows remote attackers to interrupt service via network traffic. The macb_tx_poll function frees transmitted socket buffers with napi_consume_skb while tx_ptr_lock has disabled interrupts, invoking a softirq-only path in an invalid context. Only systems using an affected MACB/GEM interface are exposed; a remote peer triggers the invalid path without credentials, disrupting availability.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux Kernel MACB/GEM network driver allows remote attackers to interrupt service via network traffic. The macb_tx_poll function frees transmitted socket buffers with napi_consume_skb while tx_ptr_lock has disabled interrupts, invoking a softirq-only path in an invalid context. Only systems using an affected MACB/GEM interface are exposed; a remote peer triggers the invalid path without credentials, disrupting availability.

The record

CVE
CVE-2026-31563
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 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=5430388a81113e62a2d48b5d7dc1e76231908ebf <78c8b090a3d5c1689dc989861b0163180db2b3f8
  2. Affected versionversion=6.17
  3. Affected versionversion=6bc8a5098bf4a365c4086a4a4130bfab10a58260 <647b8a2fe474474704110db6bd07f7a139e621eb
  4. Affected versionversion=6bc8a5098bf4a365c4086a4a4130bfab10a58260 <ca4d05afb4683d685bb2c6fccae4386c478f524a
  5. Affected versionversion=6bc8a5098bf4a365c4086a4a4130bfab10a58260 <f4bc91398b579730284328322365afa77a9d568f
  6. Affected versionversion=7db8aa3fc4ed0a2928246747b2514b0741a8187e <984350b37372f79f71d4f0a5264c640e40daf9ce
  7. Affected versionversion=a4cb0a15ab8e6d06c08229a2c7bdbe1f2454473f
  8. Affected versionversion=aeeafeb29b1b270302a9a85a13f7d70a68a3b9e6 <92e7081f0c79d9073087e54bab745bb184192c2e

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5430388a81113e62a2d48b5d7dc1e76231908ebf <78c8b090a3d5c1689dc989861b0163180db2b3f8; version=6.17; version=6bc8a5098bf4a365c4086a4a4130bfab10a58260 <647b8a2fe474474704110db6bd07f7a139e621eb; version=6bc8a5098bf4a365c4086a4a4130bfab10a58260 <ca4d05afb4683d685bb2c6fccae4386c478f524a; version=6bc8a5098bf4a365c4086a4a4130bfab10a58260 <f4bc91398b579730284328322365afa77a9d568f; version=7db8aa3fc4ed0a2928246747b2514b0741a8187e <984350b37372f79f71d4f0a5264c640e40daf9ce; version=a4cb0a15ab8e6d06c08229a2c7bdbe1f2454473f; version=aeeafeb29b1b270302a9a85a13f7d70a68a3b9e6 <92e7081f0c79d9073087e54bab745bb184192c2e

Published CVSS scores

7.5kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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

See the directory against your own environment.

Your stack

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