VulnerabilityPublished 17 Sep 2026Updated 19 Oct 2026

CVE-2026-93091: Linux kernel · firmware: arm_scmi: Quiesce notifications before teardown

Affects Linux kernelSource GCVE Database

Authoritative record:CVE-2026-93091· High

Not known to be exploited.

Data as of 26 Oct 2026, 17:16 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-38.38 23 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1017.17 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1016.16 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 13 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected 7.0.0-1002.3 – 7.0.0-1008.9 6 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available that properly quiesces notifications before teardown and synchronizes late-init work to prevent use-after-free. Users should apply the official kernel updates that include this fix. Since this is a Linux kernel vulnerability, remediation involves updating to patched kernel versions. No additional mitigation steps are indicated by the vendor advisory.

Description

A use-after-free vulnerability in the Linux kernel's arm_scmi firmware notification handling was resolved. The flaw occurs because notifications can be delivered after the notification instance is cleared during teardown, leading to dereferencing freed memory. Additionally, a lifetime issue with the notification late-init worker can cause access to freed memory if work is pending during resource release. The fix involves properly quiescing notifications before teardown and synchronizing work to prevent use-after-free conditions.

Impact

The vulnerability can lead to kernel memory corruption due to use-after-free conditions in the arm_scmi firmware notification handling. This may cause system instability or crashes. There is no indication of known exploits in the wild. The impact is limited to affected Linux kernel versions running on systems using this firmware interface.

Summary

CVE-2026-93091 addresses a use-after-free vulnerability in the Linux kernel's arm_scmi firmware notification subsystem. Specifically, scmi_notification_exit() clears and releases the notification instance, but transport callbacks may still deliver notifications until TX/RX channels are freed. This timing window allows an RX interrupt to invoke scmi_notify() while the notification state is being torn down, causing dereference of freed memory. A similar issue exists on the probe error path. Additionally, the notification late-init worker queues work on the system workqueue without proper synchronization, risking dereference of freed notification instances if the devres group is released while work is pending. The remediation involves quiescing the notification core before tearing down TX/RX channels and using disable_work_sync() to ensure no late-init work remains queued or running before channel teardown.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-93091
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:16.04:LTS, Ubuntu:18.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:26.04:LTS

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Oct 2026, 23:29 UTC

Technical details

References

Community reviews

Related threats