CVE-2026-90301Network attack vectorHinoki check available

Kernel memory corruption via heartbeat lifetime race

Published Sep 17, 2026 · Updated Sep 18, 2026

Use-after-free in Linux OCFS2 4.7 through 7.2.5 allows remote attackers to corrupt kernel memory via heartbeat negotiation traffic. Heartbeat-region handlers publish o2hb_region before delayed work is initialized and can remain reachable by queued o2net callbacks after teardown frees it. An accepted cluster peer must win an initialization or teardown race; successful exploitation can crash or fence the node or hijack kernel control flow.

CVSS severity8.1
High
EPSS probability0.53%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Use-after-free in Linux OCFS2 4.7 through 7.2.5 allows remote attackers to corrupt kernel memory via heartbeat negotiation traffic. Heartbeat-region handlers publish o2hb_region before delayed work is initialized and can remain reachable by queued o2net callbacks after teardown frees it. An accepted cluster peer must win an initialization or teardown race; successful exploitation can crash or fence the node or hijack kernel control flow.

The record

CVE
CVE-2026-90301
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=34069b886f95356d68bf8315fa648c4ab3193cdd <011291b70ba4832e136b7b581825b2bc0f525bf6
  2. Affected versionversion=34069b886f95356d68bf8315fa648c4ab3193cdd <b5a2907bdeced0949bcddc84b95ba7d4cb93841b
  3. Affected versionversion=4.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=34069b886f95356d68bf8315fa648c4ab3193cdd <011291b70ba4832e136b7b581825b2bc0f525bf6; version=34069b886f95356d68bf8315fa648c4ab3193cdd <b5a2907bdeced0949bcddc84b95ba7d4cb93841b; version=4.7

Published CVSS scores

8.1Linux CNACVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:L/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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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