CVE-2026-90276Hinoki check available

Freed-memory access via teardown timer rearming

Published Sep 17, 2026 · Updated Sep 17, 2026

Use-after-free in Linux 6.18 md-llbitmap allows local users to trigger access to freed kernel memory during bitmap teardown. llbitmap_destroy() deletes pending_timer while daemon_work remains active, allowing dirty chunks awaiting flushing to rearm the timer after its target is freed. Reaching the race requires lockless MD bitmap teardown; vendor assessments identify privileged local access, not remote exploitation.

CVSS severity4.7
Medium
EPSS probability0.21%
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 6.18 md-llbitmap allows local users to trigger access to freed kernel memory during bitmap teardown. llbitmap_destroy() deletes pending_timer while daemon_work remains active, allowing dirty chunks awaiting flushing to rearm the timer after its target is freed. Reaching the race requires lockless MD bitmap teardown; vendor assessments identify privileged local access, not remote exploitation.

The record

CVE
CVE-2026-90276
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5ab829f1971dc99f2aac10846c378e67fc875abc <5553d64e01d9a995be6c3de38501c6dd4ceede3b
  2. Affected versionversion=5ab829f1971dc99f2aac10846c378e67fc875abc <bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c
  3. Affected versionversion=5ab829f1971dc99f2aac10846c378e67fc875abc <c55aa6c17f019b6296952d336939891efa084c06
  4. Affected versionversion=6.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5ab829f1971dc99f2aac10846c378e67fc875abc <5553d64e01d9a995be6c3de38501c6dd4ceede3b; version=5ab829f1971dc99f2aac10846c378e67fc875abc <bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c; version=5ab829f1971dc99f2aac10846c378e67fc875abc <c55aa6c17f019b6296952d336939891efa084c06; version=6.18

Published CVSS scores

4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:H
4.7SUSECVSS: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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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